Question

In the following figure, AB and CD are two diameters of a circle perpendicular to each other and OD is the diameter of the smaller circle. If OA = 7 cm, find the area of the shaded region. 

 

 

Answer 1

It is given that AB and CD are two diameters of a circle perpendicular to each other and OD is the diameter of small circle.

It is given that,  `OA=7 cm`

So, radius r of small circle is 

`r=7/2 cm`

`   =3.5 cm`

We know that the area A of circle of radius r is`A=pir^2`. 

Substituting the value of r in above formula,

`A=22/7xx3.5xx3.5`

`=154 cm^2` 

Hence, 

`"Area of shaded region= Area of large circle -Area of small circle"`

`=145-38.5`

`=115.5 cm^2`