Question

As shown in the diagram , rectangle ABCD is a metal sheet in which CD= 20CM and BC= 14cm . From it , a semicircle with a diameter BC and a sector with centre A and radius AD is cut off . Find the area of the remaining sheet

Answer 1

Solution:-

Since BC is the diameter, so radius = d/2 = 14/2 = 7 cm

Radius = 7 cm

Area of the semicircular portion = 1/2πr²

= 1/2*22/7*7*7

Area of the semicircular portion = 77 sq cm

Area of the rectangle ABCD = L*B

= 20*14

Area of the rectangle ABCD = 280 sq cm

Now area of the remaining part of the paper = Area of the rectangle ABCD - Area of the semicircular portion

= 280 - 77 

= 203 sq cm