33

In the given figure, ABCD is a square of side 7 cm, DPBA and DQBC are quadrants of circles each of the radius 7 cm. Find the area of shaded region.

Given:

Side of square = 7 cm

Radius of each quadrant = 7 cm

Area of square = side × side = 7 × 7 = 49 cm^{2}

∵ Area of quadrant = πr^{2}

∴ Area of 2 quadrants = 2 × × πr^{2}

= × × 7 × 7

= 77 cm^{2}

Area of shaded region = Area of 2 quadrants – Area of square

= 77 – 49 = 28 cm^{2}

__Hence, the area of shaded region is 28 cm ^{2}.__

33

34

In the given figure, OABC is a quadrant of a circle with centre O and radius 3.5 cm. If OD = 2 cm, find the area of the shaded region.

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