hitunglah luas sisi bola dengan jari jari berikut a. 3,5 cm b. 7 cm c. 10cm d . 20cm

Luas permukaan bola = 4 × phi × r^2

a. 4 × 3,14 × 3,5^2
= 4 × 3,14 × 12,25
= 4 × 38,465
= 153,86 cm^2

b. 4 × 22/7 × 7^2
= 4 × 22 × 7
= 88 × 7 = 616 cm^2

c. 4 × 3,14 × 10^2
= 4 × 3,14 × 100
= 4 × 314 = 1.256 cm^2

d. 4 × 3,14 × 20^2
= 4 × 3,14 × 400
= 4 × 1.256 = 5.024 cm^2