A cubical block of side 7 cm is surmounted by a hemisphere. Find the surface area of the solid.

Use π = 22/7.

Question

A cubical block of side 7 cm is surmounted by a hemisphere Find the surface area of the solid Use 227

Accepted Answer

It is given that each side of cube is 7 cm. So, the radius will be 7/2 cm.

NCERT Solutions - Mathematics , Class 10 chapter Surface Areas and Volumes Question 5 Solution image

We know,

The total surface area of solid (TSA) = surface area of cubical block + CSA of hemisphere – Area of base of hemisphere

∴ TSA of solid = 6×(side)²+2πr²-πr²

= 6×(side)²+πr²

= 6×(7)²+(22/7)×(7/2)×(7/2)

= (6×49)+(77/2)

= 294+38.5 = 332.5 cm²

So, the surface area of the solid is **332.5 cm²**

NCERT Solutions Class 10 Mathematics Solutions for Surface Areas and Volumes - Exercise 13.1 in Chapter 13 - Surface Areas and Volumes