Hitunglah luas lingkaran berikut a d = 21 cm b r = 21 cm c r = 30 cm​

Jawaban:

a. L = πr² = π(21/2)² = (441/4)π cm²

b. L = πr² = π(21)² = 441π cm²

c. L = πr² = π(15)² = 225π cm²

π = 22/7 atau 3,14