Question

A wooden toy is made by scooping out a hemisphere of same radius as of cylinder, from each end of a wooden solid cylinder. If the height of the cylinder is 20 cm and its base is of radius 7 cm, find the total surface area of the toy.

Answer 1

Given, r = 7 cm and h = 20 cm

Total surface Area of Toy = CSA of cylinder + (inner CSA of Hemisphere) × 2

= 2πrh + (2πr²) × 2

= 2πrh + 4πr² 

= 2πr(h + 2r)

= `2 xx 22/7 xx 7(20 + 2 xx 7)`

= 44 (34)

= 1496 cm²