bisa bantu gak kak ????

luas arsir
= 40°/360° x 1/4 πd²
= 1/9 x 1/4 x 22/7 x 21 x 21
= 1/9 x 1/2 x 11 x 3 x 21
= 1/2 x 77
= 38,5

#semoga membantu