Question

PQRS is a rectangle in which PQ = 20 cm and QR 10 cm. A semicircle is drawn with centre at O and radius
10√2 cm. It passes through A and B as shown in the figure. Find the area of the shaded region. (Use n = 3.14)
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Answer 1

Answer:

Area of rectangle = 20×10 = 200

The chord PQ subtends angle 90 degree at centre O

So area of ∆ OPQ = 10√2×10√2/2 = 100

Area of sector OPQ π×10√2×10√2/4 (since angle POQ = 90) = 50π

So area of minor segment on PQ = area of sector OPQ - area of ∆ OPQ

50π -100

Subtract this from the area of rectangle

200- (50π -100) = 300-50π Ans