Question

find area of shaded region ​

Answer 1

Given : Figure

To find : Area of shaded region

Solution :

We know that area of a circle is given by πr² where r represents radius and π is a constant value.

We can find the area of shaded region by substracting the areas of two unshaded semi circles of diameter 10.5 m from the area of whole circle of diameter 21 m.

Assume the radius of big circle be R and that of small semi circle be r.

We know that radius = diameter /2

So,

Area of shaded region = Area of whole circle - area of semi circle - area of semi circle

Area of shaded region = πR² - πr²/2 - πr²/2

Area of shaded region = 22/7 × ( 21 × 21 ) / 4 - 22 / 7 × 10.5 × 10.5 / 4 m²

Area of shaded region = 346.5 - 86.625 m²

Area of shaded region = 259.87 m²

So the required area of shaded region is 259.87 m².