Question

If the surface area of a sphere is $154c{m}^2$, find its radius.

Answer 1

Given surface area sphere $=154sqcm$

Then $4\pi r^2=154$

$\Rightarrow 4\times \frac{22}{7}\times r^2=154$

$\Rightarrow r^2=\frac{154\times 7}{22\times 4}=12.25$

$\Rightarrow r=3.5cm$

So the radius is $3.5cm$