Question

find the total surface area of a hemisphere , whose radius is 7cm.?

Answer 1

the total surface area of a hemisphere = 3 * pi * radius * radius hence the total surface area of a hemisphere of radius 7 cm 
= 3 * ( 22 / 7 ) * 7 * 7 
= 3 * 22 * 7 
= 21 * 22
 = 462 cm sq

Answer 2

Answer:

the total surface area of a hemisphere , whose radius is 7cm  is  462cm²

Step-by-step explanation:

we have to find the value of total surface area of a hemisphere whose radius is 7cm.

formula for total surface area of a hemisphere is 3πr² cm²

substitute value of 'r' = 7cm in above equation.

total surface area of a hemisphere = 3π(7²)cm²

= 3π(7)(7) cm²

= 3π(49)cm²

π can be written as 22/7

substitute value of π = 22/7

total surface area of a hemisphere =  3π(49)cm²

= (3)(22/7)(49)

= (3)(22)(49/7)

= (3)(22)(7) = (21)(22) = 462 cm²

the total surface area of a hemisphere , whose radius is 7cm  is  462 cm²