Two equal circles intersect so that there centres, and the point at which they intersect from a square of side 1 cm. The area (in sq. cm) of the portion that is common to the circles is
A. $$\frac{\pi }{4}$$
B. $$\frac{\pi }{2} - 1$$
C. $$\frac{\pi }{5}$$
D. $${\sqrt 2 - 1}$$
Answer: Option B
Solution (By Examveda Team)

Now, Area of arc AC1B $$ = \pi {r^2}.\frac{{90}}{{360}} = \frac{\pi }{4}{\left( 1 \right)^2} = \frac{\pi }{4}$$
And area of arc AC2B = $$\frac{\pi }{4}$$
Area of square = (side)2 = 1
Area of common portion = area of arc (AC1B + AC2B) - Area of square
$$\eqalign{ & = \frac{\pi }{4} + \frac{\pi }{4} - 1 \cr & = \frac{\pi }{2} - 1\,{\text{sq}}{\text{. m}} \cr} $$
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