how to find CSA of a hemisphere whose diameter is 14cm

Question

i just want to get this answer fast as you can

 

Answer 1

The CSA (curved surface area of a hemisphere) is:    2Πr²

 

Note that 14 is a "magic number" (a number that makes the calculation easy so that you may concentrate on solving the problem), so use 22/7 as the approximation for Π.

 

CSA = 2Πr²

CSA = (2)(22/7)(14)(14)

CSA = 1232 cm²