Jawab:
1. 21 Cm, 42 Cm, 132 cm, 1,386 Cm²
2. 8 cm, 16 cm, 50.24 cm, 200,96 Cm²
3. 10 cm, 20 cm, 62.8 cm, 314 cm²
4. 7 cm, 14 cm, 44 cm, 154 cm²
5. 10 cm, 20 cm, 62.8 cm, 314 cm²
Penjelasan dengan langkah-langkah:
Jari-jari
1. 21 Cm
2. 8 Cm
3. 10 Cm
20:2 = 10
4. 7 Cm
keliling = 2 x phi x r
44 = 2 x 22/7 x r
44 = 44/7 x r
44 x 7/44 = r
r = 7
5. 10 Cm
luas = phi x r²
314 = 3.14 x r2
314:3.14 = r²
r² = 100
r = √100
r = 10
Diameter
1. 21 x 2 = 42
2. 8 x 2 = 16
3. 20 cm
4. 7 x 2 = 14 cm
5. 10 x 2 = 20 cm
Keliling ( 2πr )
1. 22/7 x 2 x 21 =132 cm
2. 3.14 x 2 x 8 = 3.14 x 64 = 50.24 cm
3. r = 10
2 x 3.14 x 10 = 62.8 cm
4. 44
5. 3.14 x 10 x 2 = 62.8 cm
Luas ( πr² )
1. 22/7 x 21 x 21 = 66 x 21 = 1,386 cm²
2. 3/14 x 8 x 8 = 200.96 cm²
3. r = 10
3.14 x 10 x 10 = 314 cm²
4. 22/7 x 7 x 7 = 154 cm²
5. 314 cm²