diketahui luas lngkaran = 3850 pi = 22per7 tentukan: a.jari jari b.diameter

L = π × r²
3.850 = 22/7 × r²
22/7 × r² = 3.850
r² = 3.850 × 7/22
r² = 1.225
r = √1.225
r = 35 cm

d = 2 × r
= 2 × 35
= 70 cm