Tolong dong yang bisa dijawab besok dikumpulin pliss

a) 60°/75° x 50 cm^2 = 40 cm^2
b) 60°/360° phi.r^2 = 40 cm^2
= 1/6 x 22/7 x r^2 = 40 cm^2
= 22/42 x r^2 = 40 cm^2
= 11/21 x r^2 = 40
= r^2 = 40 x 21/11
= > r^2 = 840/11
r = akar 840/11
c) luas lingkaran = phi.r^2
= 22/7 (akar 840/11)^2
= 22/7 x 840/11
= 2/7 x 840
= 1.640/7
= 235 5/7 cm^2