Luas lingkaran 2.464 cm. Brp diameter lingkaran tsb?

Luas = 2.464 cm²
π.r² = 2.464
22/7 x r² = 2.464
r² = 2.464 : 22/7
r² = 2.464 x 7/22
r² = 112 x 7
r² = 784
r = √784
r = 28 cm

D = 2 x r
    = 2 x 28 cm
    = 56 cm

L = phi x r^2
2464 = 22/7 x r^2
akar (2464 x 7/22) = r
r = 28
diameter = 2 x 28 = 56