If you open math book you will find a lot of mathematical

questions but you should have solve this question.

It is from class 10 rd sharma chapter 15.4 mensuration .

In this question we have to find the area of the shaded

region given that OE = 20 cm. In sector OSFT, square OEFG is inscribed.

Itâ€™s seen that, OEFG is a square of side 20 cm.

So its diagonal = âˆš2 side = 20âˆš2 cm

And, the radius of the quadrant = diagonal of the square

Radius of the quadrant = 20âˆš2 cm

So,

Area of the shaded portion = Area of quadrant â€“ Area of square

= Â¼ Ï€r2 â€“ side2

= Â¼ (22/7)(20âˆš2)2 â€“ (20)2

= Â¼ (22/7)(800) â€“ 400

= 400 x 4/7 = 1600/7 = 228.5 cm2