yang tahu mohon jwawabanya

No 3a
d^2 = 20^2 - 16^2
d^2 = 400 - 256
d^2 = 144
d = 12 cm
r = 12/2 = 6 cm

Luas arsir = 1/2 x phi x r x r
L = 1/2 x 3,14 x 6 x 6
L = 3,14 x 3 x 6
L = 56,52 cm^2

No 3b
DC^2 = 20^2 - 12^2
DC^2 = 400 - 144
DC^2 = 256
DC = 16 cm

Luas arsir = 1/2 x 12 x 16 + 1/2 x 20 x 15
L = 6 x 16 + 10 x 15
L = 96 + 150
L = 246 cm^2