Question

From a circular sheet of radius 5 cm a circle of radius 3 cm is removed. Find the area of the remaining sheet.

Answer 1

Radius of the outer circle R = 5 cm 

Radius of the inner circle r = 3 cm 

Area of the remaining sheet = Area of the outer circle – Area of the inner circle 

= πR² – πr² sq. units 

= π(R² – r²) sq. units 

= \(\frac{22}{7}\)(5² – 3²) cm² 

= \(\frac{22}{7}\) x (5 + 3) (5 – 3) 

= \(\frac{22}{7}\) x (8) (2) 

= \(\frac{352}{7}\)

= 50.28 cm²