Question

The radius of sphere is r cm.It is divided into two equal parts.find the whole surface of two parts

Answer 1

the answer is 9.4285 r.r

Answer 2

Answer:

$18.857r^2 unit^2$

Step-by-step explanation:

We are given a sphere of radius r .

It is divided into two equal parts.

So, the resultant will be two hemispheres of radius r .

Total surface area of hemisphere = $3 \pi r^2$

So, Total surface area of 2 hemisphere = $2(3 \pi r^2)$

                                                                  = $6 \times \frac{22}{7} \times r^2$

                                                                  = $18.857r^2$

Hence the whole surface of two parts is  $18.857r^2 unit^2$