Q16 of 79 Page 229

If the curved surface area of a solid sphere is 98.56 cm2, then find the radius of the sphere.

Given : CSA of sphere = 98.56 cm2

To find : Radius of sphere = r = ?


Formula : CSA of sphere = 4r2


Solution : CSA of sphere = 4r2


⇒ 4r2 = 98.56


4 × × r2 = 98.56


r2 = = 7.84


⇒ r = 2.8 cm


∴ The radius of the solid sphere is 2.8 cm.


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