Question

From a rectangular sheet of paper ABCD with AB = 40 cm and AD = 28 cm, a semicircular portion with BC as diameter is cut off. Find the area of the remaining paper. 

Answer 1

We know that the opposite sides of rectangle are equal

∴ AD = BC = 28 cm
Now, Radius of semicircular portion` =1/2"BC = 14 "cm" `

∴ Area of remaining paper = Area of rectangular sheet −Area of semicircular portion

`= 40xx28-1/2(22/7xx14xx14)`

= 1120 - 308

= 812 cm²

Hence, the area of the remaining paper is 812 cm²