Tolong di jawab ya......

A. L lingkaran 22/7*70^2=22/7*4900=22*700=15400
B. L lingkaran 3,14 *50^2=3,14*2500=7850 dibagi 1/4 = 1962,5
C. L lingkaran 3,14 *50^2=3,14*2500=7850 dibagi 1/2 =3925
Maaf yang tadi lupa gak saya bagi 1/4 sama 1/2

a.
L = πr²
L = 22/7 x 70²
L = 22/7 x 70 x 70
L = 22 x 10 x 70
L = 15.400 cm²

b.
L = 1/4 πr²
L = 1/4 . 3,14 . 50²
L = 1/4 . 3,14 . 2.500
L = 1.962,5 cm²

c.
D = 100 cm
r = 1/2 x D = 1/2 x 100 = 50 cm
L = 1/2 πr²
L = 1/2 . 3,14 . 50²
L = 1/2 . 3,14 . 2.500
L = 3.925 cm²