Question

the surface area of sphere is 1018 2/7 square cm. what is it's volume ?
( plz help me out frnds )

Answer 1

Given surface area of the sphere = 1018  2/7 cm²
⇒ 4πr² = 1018  2/7
⇒ 4 × 22/7 r² = 7128/7
⇒ 88/7× r² = 7128/7
⇒   r² = (7128/7) × (7/88)
⇒   r² = 7128/88
⇒   r² = 81
⇒   r = √81 = 9
∴Radius = 9cm
Volume of the sphere = 4/3πr³  
= 4/3  ×  22/7 × 9³
=88/21 × 729
=64152/21
=3054.9 cm³

Answer 2

Step-by-step explanation:

surface area of sphere is 1018 2/7=7128/7

$surface \: area \: of \: sphere \: is \: 1018 \times \frac{2}{7 } = \frac{7128}{7} {cm }^{2} \\ 4\pi {r}^{2} = \frac{7128}{7} \\ {r}^{2} = \frac{7128}{4 \times 22} = 81 \\ {r}^{2} = {81}^{3} \\ {r}^{2} = {81}^{3} {cm}^{2} \\ {r}^{2} = 9cm \\ so \: the \: volume \: ofsphere \: = \frac{4}{3} \pi {r}^{3} \\ \frac{4}{3} \times \frac{22}{7} \times {9}^{3} \\ \frac{4 \times 22 \times 9}{7} \\ = 3054.9 {cm}^{3}$