Observation #2 The Event Held in BKR School – Mother’s Day

We were really lucky to be assigned in Thailand, especially in BKR School in August. It’s because there were so many events held by the school. For this post, I will share Mother’s Day in Thai.

Unlike in Indonesia, Thai’s Mother’s day happens at every August 12. It is a day to celebrate Queen Sirikit’s Birthday, The Queen of Thailand. This is Queen Sirikit in a young age. *credit to pinterest

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What did we do to celebrate the mother’s day in BKR School?

There were dance performance, the ceremony for the queen, the display of students’ work about mother,  kneeling to moms, and many more!

IMG_20170810_085046 The picture above shows the ceremony for the Queen. All of the teachers in BKR (including us, the foreigner pre service teachers) went to the stage and paid respect for the Queen. And yeah, you see that jasmine? Queen Sirikit loves Jasmine, hence we wear jasmine as accessories in that day. Mine is down below, I wore this as a brooch. Beautiful, isn’t it?

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There was a dancing performance too! It was done by the students of lower secondary school.

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And, here is the display of students’ works and the primary students XD sorry for low quality picture anyway

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Andddd, the last, there was a kneeling to mom to, or in Indonesia we call it as “sungkem”.

IMG_20170810_094016The picture above is kindergarten students kneeled down to their mothers. It was so touching when seeing them kneeling. Awww moment. And yeah, the kneeling was not only done by kindergarten students, some representative of primary school and lower secondary school students also did it.

As I mentioned above, the mother’s day happened on August 12. For this year (2017), it happened on Saturday, meanwhile saturday is a weekend, and none go to school in weekend right. So, BKR school celebrated it on August 11, it was on Friday. What I like the most was, after this celebration, we had a free day in Monday. So I can say we had a short but long holiday, saturday, sunday and monday were free days XD

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Observation #1 – The Daily Activity of BKR School

BKR School is adapting full day school, which means the learning process is held every Monday to Friday, and it lets the students and the staffs of the school have a short break every Saturday and Sunday. The School opens at 6.30 a.m. and teachers are expected to come before 7.15 a.m.
Everyday, BKR School holds flag ceremony, it starts at 7.45 a.m.

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The students that stand the closest to the flag are lower secondary (Matthayom) students. The primary (Prathom) students stand in the middle of the row, while kindergarten (Aniban) students stand in the last row.
After the flag ceremony is over, the students perform the Buddhist prayer.

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The next is they maditate. Meditation is my favorite! Because during the meditation, the school plays the relaxing music. You can check the music below.
Flower bloom thai

And, here is the picture of students doing meditation

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After the meditation is over, the students go to the different directions. Kindergarten students go to the class directly. Primary students go and make a row in front of the class, and they will drink milk provided by the school. The lower secondary students will stay in the hall to hear some information before going to subject class.

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The picture above shows a male students helping his friend opening the milk.

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The picture above shows the announcement of certain information for lower secondary students. The picture is taken from the primary school building.
After that, all of them will enter the classes and start studying. The primary students start studying at 8.45 am, and the lower secondary students starts studying at 8.30 a.m.
The school also adopts moving class. But it only happens to primary students grade 4, grade 5 and grade 6. It also happens to all lower secondary students. But, the kindergarten, primary students grade 1 to 3 doesn’t adopt this system.

The school also provides lunch for the students and the staffs of the school. The lunch time for lower secondary students start at 11.30 until 12.30. While primary students and kindergarten students start before them.

After having lunch, the kindergarten will have a nap time. Primary students don’t have a nap time, but although they don’t have a nap time, they have to brush their teeth. After that primary students will have a meditation again before start studying again.

For lower secondary students, after the lunch time, they will have the learning process directly. All of them learn until 15.30 and then the school lets the students come back to home.

The Very First Day of SEA-Teacher Batch IV

7 August 2017

I woke up at 3 am that day. It’s due to I had not re-packed my clothes. I didn’t know that we supposed to stay only for one day in the dorm, and the following day we had to move to the school dorm. But, it didn’t happen to everyone. For those whose schools are near VRU, they didn’t need to move. I was not sure what school that I got assigned to, I just prepared everything. Just in case I had to move, I already re-packed my clothes.

In the morning Ton, the 3rd batch SEA-Teacher participant took us to the Valaya Cafetaria. My first impression seeing the cafetaria is “wow”, because it was so clean. In it, to buy the food, we have to buy some coupons. I chose to take a look first then decide what to buy. Alhamdulillah, there was Muslim Food. But unfortunatey the menu was on Thai so I couldn’t understand a single thing. The good thing is, the cafetaria had pictures of the food, so we could choose which picture seemed tempting. When the food was served, we took the fork and spoon in the different spot, and there was a hot water to sterilize them. So I put my fork and spoon in the hot water for seconds and took it away.

Finished eating, I got amazed again by the students who were really discipline. After they finished eating, they did take their plates to certain spot. There, they will separate the food residue, the plastic garbage, the fork and the spoon, the plate, and the bowl in different spot. To me, that was really good for self-discipline.

After that, we headed to the VRU building to meet the VRU President. To reach the room, we took some staircases. The unique thing is, there were some stickers telling how much the calories we burnt if we took certain staircases. I believe people will be more motivated to stay healthyby taking staircase rather than taking the lift.

Finally we arrived in the meeting room. The meeting room was so big and elegant, kind of room that I liked to stay in the long term. There, we met some great people. It looked like they already waited for us. Then the meeting was started. The President of VRU gave a warm welcoming speech to us and then Miss Nina introduced some people in that room. After that they told us about the school where we got assigned to. Turned out my school was in Boon Koom School, and I had to move out. Luckily I already repacked my clothes. And yeah, the participants who got assigned to Boon Koom were my roommates, Dina, Sarah and EL. My friend, Riski got assigned in Satit, so we were separated.

Miss Nina started to send us to the schools at 10.30s a.m. The first school we went was Chiengrak Noi School. There we were served very kindly. And because it’s lunch time, we were served some nice Thai foods, Thai snacks, and fruits. The taste was amazing.

The second school was Pakklong Song School. It was kindergarten. The beautiful thing was, when we arrived there, we realized there was a mosque and the adzan was on. That was the first time I saw a mosque and I heard a-real-azan in Thailand. And yeah, when we arrived, the kids were ready to take a nap. So cute! And yeah the school officers were also nice. We were served with a coffe and some beautiful-pastel-colors-cakes.

The third and the last school was Boon Koom. The first time I saw the school, my impression was the school was really big! And yeah it was, Boon Koom has more than 1300 students.  We directly went to the meeting room. There we met the principal, and some teachers. They truly gave us a warm welcome. They also gave us some time schedule options. Thus we can choose what level we wanted to teach. I chose to teach primary grade 5 and secondary grade 7. Oh ya, they also served us with some foods. I was realy full that day.

After discussing, they showed us the dorm. The dorm is nice. It was clean and so cozy. It was in the 2nd floor. But thanks God there was Teacher Tam helping us to take our luggage to our room. Then, we said goodbye to Miss Nina because she wanted to go back to VRU.

We started to clean and set the dorm and then we took a quick rest. Not long after that Teacher Kul and Teacher Na invited us to the market.

We were really happy when they took us to the market. They really helped us. In the market we bought so many equipments and of course food. Teacher Kul also took us to the fried-insect-seller, and she made us tasting how the insect taste like. I took a cricket aaaand the taste was amazing. Its price was 25 baht. Because I already bought an omelette, I planned to buy that different day. And we also bought rices. The rices are so good! And the price for one bowl of rice was 4 baht. The rice was different with the one I used to eat in Indonesia. It was something I couldn’t describe. You should try it yourself! After that we went back to the dorm.

Touchdown Bangkok!

August 5-6, 2017

As the plan, we would start our journey today. The plan was, we departed from Palembang at 19.50 and we would arrive Soetta Airport at 20.50. Then the following morning we would depart to Thailand at 07.05 and arrive at Thailand at 10.50. Basically, that’s the plan. But so many things happened about our journey. I am gonna tell you our stories in the following paragraphs.

As you know, the schedule of the flight was at 19.50, thus we went to the airport at 17.00 and arrived at airport at 17.30ish. Time passed and we were hungry because we hadn’t had our dinner. We remembered that the schedule would be at 19.50, so we used the time for dinner. The food was already served and we began to eat. We ate the food half way but then our name was called by the information officer. Turned out it was our final call to enter the aircraft. Riski, my friend-the-ice cream-lover , just ate her ice cream, but, since we were already called, then she just left it. While me, I took my fried chicken and then left. We ran as fast as we could. So guys, I recommend you to enter the board like 20 minutes before the scheduled time.

One hour passed by and we arrived at Soekarno-Hatta airport. Because we arrived in the evening, we planned to stay in the hotel nearby the airport. One of the facility of the hotel is free shuttle bus. Because we already arrived, we called the hotel and asked them to pick us up. But unfortunately we had to wait for it for almost one hour due to the traffic jam. But yeah the good thing is they pick us up freely and we were sent to the hotel safe and sound.

 

Arrived in the hotel we didn’t decide to sleep directly, we ate some cookies instead. Then, about 00.30 am we slept. Meanwhile we had to wake up again at 3 am because the shuttle bus would send us to the airport at 04.00 am. I woke up at 2.50 am then I began to bath and woke my friends up. Then at 4 am we went to airport.

The first thing we did was going to A*rasia office to ask several things (it’s our first time going abroad without any guide and we didn’t wanna make any mess). Then the officer helped us to do the self-check-in. After that we went to do manual check in again because of luggage. Then we headed to immigration. Then we went to the terminal and wait in the waiting lounge before departing to Thai.

The funny thing when we waited in the terminal was my friend bought three bottles of mineral water and they had to leave it in the immigration due to the law. You know everything is expensive in the airport, including the water. But the law is the law right. So they had to leave that pricey-but actually cheap-things in the immigration. Luckily there was a free-ready-to-drink-water-machine, so we used that machine to get some water.

Time passed by and we had to board the aircraft. We took Air As*a XT 250 as our flight. During the flight, I slept for about 2 hours in the beginning of the flight, it’s due to lack of sleep. I spent my last one hour and more with adoring the scenery from above. The beautiful of the scenery made me forget the time. My more than 3 hours flight reached its end, the aircraft landed and we finally touched down.

The first thing we did was going to the rest room. Then we went to the immigration. After that we claimed our luggage. Then we checked our line group, turned out Miss Nina had already been waiting for us in the gate 3. So we reached her and there were two youth heading to our direction. Turned out it was VRU representative. Then they took us to where other participants gathered. They also told us that each of us would get buddies. Unfortunately my buddy was not there, they only told me the name of buddy was Zacd. Not long after that we got to the van to VRU.

When we arrived VRU, we directly got to the dorm. Another representative of VRU told me that my room was 114 and my room mates were Dina, Sarah and El. Along the way to the gate of the dorm, there were so many bycicles, and we also saw some washing machines, then we found the gate. My room is close to the gate, so I could see the number tag directly.

I went inside my room, and it is so nice. The room got fan, air conditioner, 2 bunk beds, 4 tables for studying, 4 wardrobes, water heater, and some power outlets. When we reached the room, we directly put our clothes in the wardrobe. Due to tiredness, we decided to have a rest. After that some buddies took us to know more about VRU area. We went to Family Mart to buy some foods. After that we got back to the room to eat and at 5.30 pm they took us to the Lotus Mall to buy sim card. Before that I met my buddy, Zacd.

In the mall, it’s kinda hard for us to have the right sim card, but thanks to all of the buddies, we got the right sim card. It was Tr*e move. The sim card’s costs was 49 baht and the data package was 540 baht (including the tax). It a 4g package data with unlimited data plan. After that we went back to the dorm to rest.

SEA-Teacher

Sea Teacher is a program for pre-service studenst to teach in ASEAN countries for one month. Sea teacher has three objectives, they are (1) to enable the students to develop their teaching skills and pedagogy, (2) to encourage the students to practice their English skills and (3) to allow the students to gain broader regional and world view.

This year (2017) the sea teacher is having 4th batch. Fortunately I am the part of it. The countries that join it are Indonesia, Thailand and Philippine. Thus, there are students who comes from Indonesia will teach either in Philippines or Thailand. Then the Thai students will teach either in Indonesia or Philippines. And the Pinoy students will teach either in Thailand or Indonesia. I am Indonesian student and I am assigned in Thailand, and my host university is Valaya Alongkorn Rajabhat University (VRU).

The first activity we did was a trial conference. The next activity was interview via WebEx. We were asked about our major, the subject that we would like to teach and what level of education we prefer to teach. After that we were given the information about our host university. Then, we were joining a line group chat. The members of it are the students whose the host university is VRU. In that group we talked about many things related to the program. Then a day before we went to Thailand,  there were online conference for the final preparations. In online conference Seameo made sure we would bring some documents, the appropriate dress, and others related to our departing.

There are some documents that we have to bring, they are passport, letter of acceptance from host university, letter of duty from home university, travel insurance, the letter of permission from parents. For indonesian, you can make a passport in immigration office , and the price for 48 pages passport was IDR 355.000, and because the program will only last one month or less, you don’t need to have a visa. The letter of acceptance is given by the coordinator of host university that joins the line group chat. You can ask the letter of duty to your home university coordinator. For travel insurance, we (UNSRI) use Deluxe TravelPro by Allianz. And the last, the letter of permission is signed by parents.

Our other preparation in home university was peer teaching and micro teaching with English as the language of instruction. But due to misunderstanding, I did my peer teaching with Bahasa and I started speaking English in micro teaching. We also made the study plan in English, thus we would get used to speak and write in English.

So I think that’s all the preparation that I did for Sea Teacher. I will post about my days in Thailand. Stay tuned 🙂

 

Jurnal Pendidikan Matematika

Assalamualaikum

Berikut ini adalah list jurnal pendidikan matematika di Indonesia.

 

http://jims-b.org/ Himpunan Matematika Indonesia

http://ejournal.unsri.ac.id/index.php/jpm Unsri

http://p4tkmatematika.org/category/08produk/01jurnal/ EduMath

http://ejournal.unesa.ac.id/ Unesa

http://jurnal-online.um.ac.id/article/31 UNM

http://journal.uny.ac.id/index.php/jrpm UNY

http://admathedu.uad.ac.id/wp/ UAD

http://id.portalgaruda.org/?ref=browse&mod=viewjournal&journal=519

http://journal.fpmipa.upi.edu/index.php/jopmk UPI

http://fkip.untirta.ac.id/jurnal/index.php/jppm/index UNTIRTA

http://fkip.ustjogja.ac.id/jurnal-pend-matematika-union/ UST

http://online-journal.unja.ac.id/index.php/edumatica UNJA

http://www.jurnal.unsyiah.ac.id/DM Unsyiah

http://fkip.ummetro.ac.id/journal/index.php/matematika Ummetro

http://jurnal.fkip.unila.ac.id/index.php/MTK Unila

http://matematika.unnes.ac.id/jurnal/ Unnes

http://lppm.stkippgri-sidoarjo.ac.id/index.php?pilih=mat&modul=yes&action=mahasiswa Stkip pgri

http://matematika.fmipa.unp.ac.id/e-journal/ UNP

http://jurnal.unimus.ac.id/index.php/JPMat Unimus

http://jmpunsoed.com/ Unsoed

http://jurnal.fkip.uns.ac.id/index.php/matematika UNS

http://matematika.ub.ac.id/penelitian-dan-pengabdian/jurnal-nasional-internasional/ UB

 

Disalin dari: http://sholihatunnisa96.blogspot.co.id/2016/03/jurnal-pendidikan-matematika.html

Soal dan Pembahasan Sudut Pusat dan Keliling Lingkaran

Soal No. 6
Perhatikan gambar!

Tentukan besar:
a) ∠PQR
b) ∠QOR

Pembahasan
a) ∠ PRQ adalah sudut keliling yang menghadap sebuah busur yang memiliki tali busurnya merupakan diameter lingkaran (garis PQ). Sudut keliling yang demikian memiliki besar 90°.

Dari sifat segitiga (jumlah ketiga sudutnya adalah 180°) dapat ditentukan besar sudut PQR:
∠PQR = 180 − 90 − 20 = 70°

b) ∠ QOR = 2 × ∠ RPQ = 2 × 20° = 40°

Soal No. 7
Perhatikan gambar!

Tentukan besar:
a) ∠BCD
b) x

Pembahasan
a) ∠BCD
Pada kasus ini ∠BCD berhadapan dengan ∠ BAD (bukan sehadap ya,.tapi berhadapan,.) sehingga jumlahnya adalah 180°
∠BCD + ∠BCD = 180°
∠BCD = 180° − ∠ BAD = 180 − 60° = 120°

b) x
5x = 120°
x = 120° / 5 = 24°

Soal No. 8
Perhatikan gambar berikut!

Pusat lingkaran berada di titik O. Jika ∠ABE + ∠ACE + ∠ADE = 96°, maka besar sudut ∠AOE adalah….
A. 32°
B. 48°
C. 64°
D. 84°

Pembahasan
∠ABE, ∠ACE dan ∠ADE adalah tiga sudut yang sama besarnya, karena sudut keliling yang menghadap satu busur yang sama, yaitu busur AE. Misalkan besarnya adalah x.

∠ABE + ∠ACE + ∠ADE = 96° x + x + x = 96°
3x = 96°
x = 96/3 = 32°

Sementara itu ∠AOE adalah sudut pusat yang juga menghadap busur AE, jadi besarnya adalah dua kali dari x.

∠AOE = 2x
= 2(32) = 64°

Soal No. 9
Perhatikan lingkaran berikut, pusat lingkaran di titik O.

Diketahui:
∠ABD + ∠AOD + ∠ACD = 140°

Besar ∠ABD =…..
A. 30°
B. 35°
C. 40°
D. 45°

Pembahasan
∠ABD dan ∠ ACD sama besar, misalkan sebagai x. Besar ∠AOD adalah dua kali ∠ABD, misalkan 2x. Sehingga:
∠ABD + ∠AOD + ∠ACD = 140°
x + 2x + x = 140°
4x = 140°
x = 140/4 = 35°

Jadi besar ∠ABD = 35°

Soal No. 10
Titik O adalah pusat lingkaran.

∠ABC besarnya dua kali ∠CAB. Besar ∠ABC adalah…
A. 30°
B. 45°
C. 50°
D. 60°

Pembahasan
∠ACB adalah sudut keliling menghadap suatu tali busur yang panjangnya sama dengan diameter lingkaran. Sudut yang demikian itu besarnya 90°. Jumlah sudut pada segitiga ABC adalah 180°, sehingga ∠ABC + ∠ CAB = 90°

∠ABC + ∠ CAB = 90°
x + 2x = 90°
3x = 90°
x = 90/3 = 30°

Besar ∠ABC dengan begitu adalah
∠ABC = 2x = 2(30°) = 60°

Soal dan pembahasan ini disalin dari: http://matematikastudycenter.com/smp/91-8-smp-soal-pembahasan-sudut-pusat-keliling-lingkaran

Soal dan Pembahasan Sudut Pusat dan Keliling Lingkaran

Soal No. 1
Sebuah lingkaran berpusat di titik O seperti gambar berikut.

Tentukan besar sudut AOB!
Pembahasan
Sudut AOB adalah sudut pusat yang menghadap busur yang sama dengan sudut ACB yang merupakan sudut keliling. Hubungan antara sudut AOB dan sudut ACB dengan demikian adalah:
∠AOB = 2 × ∠ACB

Sehingga
∠AOB = 2 × 55° = 110°

Soal No. 2
Diberikan sebuah lingkaran sebagai berikut!

∠DFE besarnya adalah 70° dan ∠ DPE adalah (5x − 10)°. Tentukan nilai x.

Pembahasan
Variasi dari soal nomor satu dengan penggunaan sifat sudut pusat dan sudut keliling yang sama,
Hubungan antara sudut DPE dan sudut DFE dengan demikian adalah:
∠DPE = 2 ∠DFE

Sehingga
(5x − 10)° = 2 × 70°
5x − 10 = 140
5x = 140 + 10
5x = 150
x = 150/5 = 30

Soal No. 3
Diketahui:
∠AOB = 65°

Tentukan besar ∠ ACB

Pembahasan
Hubungan antara sudut ACB (sudut keliling) dan sudut AOB (sudut pusat):
∠ ACB = 1/2 × ∠ ACB
∠ ACB = 1/2 × 65° = 32,5°

Soal No. 4
Perhatikan gambar berikut!

Titik O adalah titik pusat lingkaran dan besar sudut EGH = 53°. Tentukan besar sudut EFH

Pembahasan
Baik HGE maupun EFH keduanya adalah sudut keliling. EGH dan EFH menghadap busur yang sama. Dua sudut keliling yang demikian akan memiliki besar yang sama pula. Sehingga besar sudut EFH juga 53°

Soal No. 5
Perhatikan gambar berikut!

Tentukan besar ∠ BDC dan ∠ ACD

Pembahasan
∠BDC = ∠ CAB = 30°
∠ ACD = ∠ ABD = 50°

 

soal dan pembahasan ini disalin dari http://matematikastudycenter.com/smp/91-8-smp-soal-pembahasan-sudut-pusat-keliling-lingkaran

Soal dan Pembahasan Luas dan Keliling Lingkaran

Soal No. 1
Perhatikan gambar bangun datar berikut!

Tentukan:
a) Luas daerah yang diarsir
b) Keliling bangun
Pembahasan
a) Luas daerah yang diarsir
Luas daerah yang diarsir adalah luas persegi dengan sisi 14 cm dikurangi dengan luas SETENGAH lingkaran dengan jari-jari 7 cm.
L = (s x s) − 1/2 x π x r x r
L = (14 x 14) − 1/2 x 22/7 x 7 x 7
L = 196 − 77 = 119 cm2

b) Keliling bangun
Keliling = 14 cm + 14 cm + 14 cm + 1/2× (2π × r) cm
Keliling = 42 cm + 1/2× (2 × 22/7 × 7) = 42 + 22 = 64 cm

Soal No. 2
Perhatikan lingkaran berikut!

Daerah (I) adalah juring lingkaran yang memiliki sudut pusat 50° dan daerah (II) adalah juring lingkaran yang memiliki sudut pusat 120°. Tentukan perbandingan luas daerah (II) dan daerah (II)!

Pembahasan
Luas suatu juring dengan sudut θ adalah :

Jika dua buah juring yang diketahui sudutnya dibandingkan luasnya,  diperoleh:

Soal No. 3
Selembar seng berbentuk persegipanjang berukuran 50 cm × 40 cm. Seng itu dibuat tutup kaleng berbentuk lingkaran dengan jari-jari 20 cm. Luas seng yang tidak digunakan adalah.…
A. 744 cm2
B. 628 cm2
C. 314 cm2
D. 116 cm2
(UN Matematika SMP/MTS Tahun 2005)

Pembahasan
Luas segiempat dengan ukuran 50 x 40 dikurangi luas lingkaran dengan jari-jari 20 cm:

Soal No. 4
Perhatikan gambar di samping!

Luas daerah arsiran adalah…π = 22/7
A. 40,25 cm2
B. 42,50 cm2
C. 50,25 cm2
D. 52,50 cm2
(UN Matematika SMP 2009)

Pembahasan
Luas daerah arsiran adalah luas persegipanjang ditambah dengan luas setengah lingkaran yang berjari-jari 3,5 cm.

Soal No. 5
Perhatikan gambar di samping!

a) Tentukan luas daerah bangun di atas
b) Tentukan keliling bangun di atas

Pembahasan
a) Luas persegi dengan sisi 42 cm, ditambah dengan dua kali luas lingkaran yang berjari-jari 21 cm (setengahnya 42 cm).

b) Keliling dua buah lingkaran
K = 2 × ( 2 π × r )
K = 2 × 2 × 22/7 × 21 = 264 cm

Soal No. 6
Budi berangkat ke sekolah menaiki sepeda beroda satu. Jika diameter roda sepeda adalah 50 cm dan Budi sampai di sekolah setelah roda menggelinding sebanyak 1200 putaran, perkirakan jarak rumah Budi ke sekolah!

Pembahasan
Diameter roda D = 50 cm

Keliling roda
Keliling = π D = 3,14 × 50 = 157 cm

Roda berputar sebanyak 1200 kali,  panjang lintasan atau jarak yang ditempuh roda adalah banyak putaran dikalikan keliling roda, sehingga:
Jarak = 1200 × keliling roda = 1200 × 157 cm = 188400 cm = 1884 m = 1,884 km

Soal No. 7
Sebuah roda dengan jari-jari 14 cm menggelinding di jalan hingga panjang lintasannya adalah 792 cm. Tentukan banyaknya putaran yang terjadi pada roda!

Pembahasan
Data soal:
r = 14 cm
panjang lintasan x = 792 cm
Keliling roda = 2 × 22/7 × 14 = 88 cm
Banyak putaran
n = x : keliling roda
n = 729 cm : 88 cm = 9 kali putaran

Soal No. 8
Lingkaran A memiliki diameter sebesar D, lingkaran B diameternya 3D. Perbandingan Luas lingkaran A dan lingkaran B adalah….
A. 1 : 2
B. 1 : 6
C. 1 : 9
D. 2 : 3

Pembahasan
Dari rumus luas lingkaran:
L = 1/4 πD2

LA : LB = (DA)2 : (DB)2
= D2 : (3D)2
= 1 : 9

Jadi perbandingannya 1 : 9

Soal No. 9
Perhatikan gambar!

Jika luas juring OBC = 60 cm2, luas juring AOC adalah….
A. 44 cm2
B. 76 cm2
C. 104 cm2
D. 120 cm2

Pembahasan
Dari perbandingan luas dan perbandingan sudut-sudut diperoleh



Soal No. 10
Perhatikan gambar berikut!

Diketahui panjang busur PQ adalah 60 cm. Keliling lingkaran tersebut adalah…..cm
A. 110
B. 120
C. 140
D. 160

Pembahasan
Dengan hubungan panjang busur-keliling lingkaran dan sudut diperoleh:

Soal No. 11
Perhatikan gambar berikut! ABCD adalah persegi dengan panjang AB = 50 cm.

Luas daerah yang berwarna biru adalah…..cm2
A. 1225,5
B. 1335,5
C. 1337,5
D. 1412,5

Pembahasan
ABCD persegi, sehingga diameter lingkaran adalah 50 cm dan jari-jarinya 25 cm. Luas dua segitiga yang ada dalam lingkaran adalah



Luas daerah yang diminta adalah luas lingkaran dikurangi luas dua segitiga tersebut



Soal No. 12
Perhatikan gambar berikut!

Keliling lingkaran adalah 176 cm. Besar sudut PQR adalah 45°. Luas daerah yang diarsir adalah…
A. 712 cm2
B. 616 cm2
C. 392 cm2
D. 224 cm2

Soal dan pembahasan ini disalin dari http://matematikastudycenter.com/smp/92-8-smp-soal-pembahasan-luas-keliling-lingkaran