Question

A paper is in the form of a rectangle ABCD in which AB = 20 cm and BC = 14
cm. A semicircular portion with BC as diameter is cut off. Find the area of the
remaining part.

Answer 1

Length of rectangle = 20 cm
Breadth of rectangle = 14 cm
Area of rectangle = 20 x 14 = 280 cm^2
Diameter of semicircle = 14 cm
Therefore, radius of semicircle = 7 cm
Area of semicircle = ( pi x r^2) / 2
Pi = 22 / 7
Therefore, AREA of semicircle =
(22 x 7 x 7) / (7 x 2)
= 77 cm^2

Area of remaining portion = area of rectangle
- area of semicircle
= 280 - 77
= 203 cm^2

Answer 2

Total area = 20×14 = 280 unit^2
circular area = 22×7×7 /2× 7 = 77 unit^2
remaining area = total area - circular area
= 280 - 77 = 203unit^2