Question

A hollow right circular cylinder with height 8 cm and base radius 7 cm is opened out into a rectangle. What are the length and breadth of the rectangle respectively? 

(a) 22 cm, 16 cm 

(b) 44 cm, 8 cm 

(c) 22 cm, 8 cm 

(d) 44 cm, 16 cm

Answer 1

(b) 44 cm, 8 cm

Length of the rectangle = 2πr = 2 x \(\frac{22}{7}\) x 7 cm = 44 cm

Breadth of the rectangle = Height of cylinder = 8 cm.