Question

Find the radius of a sphere whose surface area is 154 cm².

`["Assume "pi=22/7]`

 

Answer 1

Let the radius of the sphere be r.

Surface area of sphere = 154

∴ 4πr² = 154 cm²

`r^2 = ((154xx7)/(4xx22))cm^2`

   `= ((7xx7)/(2xx2))cm^2`

`r =(7/2)cm = 3.5cm`

Therefore, the radius of the sphere whose surface area is 154 cm² is 3.5 cm.