1. K=314 m

L=7.850 m²

2. K=71,4 cm

L=314 cm²

3. a.14 cm

b.44 cm

4. 3.768 cm

5. 28 m

6. 942 m²

7. a.180°

b.siku-siku

1. DIK: d=100

K=π×d

K=3,14×100

K=314 m

L=π×r²

L=3,14×50²

L=7.850 m²

2. K=1/4×2×π×r+2×r

K=1/4×2×3,14×20+2×20

K=1/4×125,6+40

K=31,4+40

K=71,4 cm

L=1/4×π×r²

L=1/4×3,14×20²

L=314 cm²

3. A.mencari radius / jari-jari

L=1/2×π×r²

308=1/2×22/7×r²

308=22/14×r²

r²=308:22/14=308×14/22

r²=4312/22=196

√196=14

B.mencari keliling

K=1/2×2×π×r

K=1/2×2×22/7×14

K=44 cm

4. L=π×r²

2.826=3,14×r²

r²=2.826:3,14

r²=√900=30

jadi, jari-jari nya adalah 30

K=2×π×r

K=2×3,14×30

K=188,4 cm

Jarak Tempuh=Keliling×Jumlah Putar

=188,4×20

=3.768 cm

5. K=π×d

88=22/7×d

d=88:22/7

d=28 m

6. d=40:2=20 (r)

L=3/4×π×r²

L=3/4×3,14×20²

L=942 m²

7. a.180°

b.siku-siku