Question

A paper is in the form of a rectangle ABCD, in which AB = 16 cm and BC = 12 cm. A semicircular portion with BC as diameter is cut off . Find the area of remaining part.
(Class 10 Maths Sample Question Paper)

Answer 1

FIGURE IS IN THE ATTACHMENT.
Solution:

Given:

Length of a rectangle (AB) = 16 cm
Breadth of a rectangle (BC) = 12 cm

Diameter of semicircle (BC) = 12 cm

Area of the rectangle = Length ×  breadth
Area of the rectangle = 12 × 16 = 192 cm²

Radius of the semicircle ,r = 12/2 = 6 cm
Area of semicircle = ½(πr²)
= ½(22/7× 6× 6)= (11 ×36)/7
= 396 /7
= 56.57 cm²

Area of the remaining part = Area of rectangle ABCD -  Area of semicircle
Area of the remaining part = 192 - 56.57 = 135.43 cm².

Hence, the Area of the remaining part = 135.43 cm².

HOPE THIS WILL HELP YOU....

Answer 2

area of rec.= 16×12=192cm^2
area of semicircle = 1/2×3.14×r^2
= 1/2×3.14×36=56.52
remaining area= 192-56.52
=135.48cm^2