A sheet of paper is in the form of a rectangle ABCD in which AB=40cm and AD=28cm. A semi-circular portion with BC as diameter is cut off. Find the area of the remaining paper.
Area of rectangle = length × breadth
Area of rectangle = 40 × 28
Area of rectangle = 1120 cm2
Diameter of semi circular portion = 28cm
Radius of semi circular portion = 
= 14cm
So,
Area of semi circular portion = 
= 308 cm2
Area of remaining portion = 1120 – 308 = 812cm2
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