Sudut pusat=180derajat Juring=157 cm2 Diameter?

r = √(157 ÷ (180°/360° × 3,14))
r = √(157 ÷ (1/2 × 3,14))
r = √(157 ÷ 1,57)
r = √100
r = 10 cm
d = 2r
d = 2(10 cm)

diameter = 20 cm