tolong cara kerjanya kh? terserah nomor berapa yg mau di jawab... TRIMAKASI

3)3,14×40=125,6(B)
4)22/7×28×28=1.232(A)
5)diameter=7/22×88=28
luas=22/7×14×14=616(C)
6)22/7×14=44(A)
7)3,14×10×10=314 cm²(D)
8)7/22×440=140 m(B)

3. K = 2 × phi× r

= 2 × 3,14 × 20

= 2 × 62,8

= 125,6 cm (B)


4. L = phi × r^2

= 22/7 × 28^2

= 22/7 × 784

= 22 × 112

= 2.464



5. K = 2 × phi × r

88 = 2 × 22/7 × r

88 = 44/7 × r

r = 88 ÷ 44/7

r = 88 × 7/44

r = 616/44

r = 14


L = phi × r^2

= 22/7 × 14^2

= 22/7 × 196

= 22 × 28

= 616 cm^2 (C)


6. L = phi × r^2

154 = 22/7 × r^2

r^2 = 154 ÷ 22/7

r^2 = 154 × 7/22

r^2 = 1.078/22

r^2 = 49 (diakarkan pangkat 2)

r^2 = 7^2 cm


K = 2 × phi × r

= 2 × 22/7 × 7

= 2 × 22 × 1

= 44 cm (A)


7. r^2 = D ÷ 2

= 20 ÷ 2

= 10^2

L = phi × r^2

= 3,14 × 10^2

= 3,14 × 100

= 314 cm^2 (D)