Q11 of 52 Page 1

From a rectangular sheet of paper ABCD with AB = 40 cm and AD = 28 cm, a semi circular portion with BC as the diameter is cut off. Find the area of the remaining paper. (Use π = 22/7)


Length (l) of the rectangular sheet of paper, AB = 40 cm


Width (b) of the rectangular sheet of paper, AD = 28 cm


Area of the rectangular sheet of paper = l × b


= 40 × 28 = 1120 cm2


Diameter of semi-circle = 28 cm


∴ Radius (r) of semi-circle = 14 cm


∴ Area of semi-circle = 1/2 πr2



= 308 cm2


∴ Area of the remaining paper = Area of the rectangular sheet of paper - Area of semi-circle


= 1120 – 308 = 812 cm2


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