Question

the area of shaded portion in the adjoining figure is​

Answer 1

Answer:

The area of the shaded portion is 66 cm²

Step-by-step explanation:

Given :

diameter of smaller circle = 4 cm

diameter of larger circle = 10 cm

To find :

the area of the shaded portion

Solution :

First, we have to find the area of the smaller circle and area of the larger circle and then subtracting the area of smaller circle from larger circle gives us the area of the shaded portion.

Area of the smaller circle :

diameter, d = 4 cm

radius = d/2 = 4/2 = 2 cm

➙ Area = πr²

➙ Area = π(2)²

➙ Area = 4π cm²

Therefore, the area of the smaller circle is 4π cm²

Area of the larger circle :

diameter, d = 10 cm

radius = d/2 = 10/2 = 5 cm

➙ Area = πr²

➙ Area = π(5)²

➙ Area = 25π cm²

Therefore, the area of the smaller circle is 25π cm²

Area of the shaded portion :

➙ Area of the larger circle - area of the smaller circle

➙ 25π cm² - 4π cm²

➙ 21π cm²

Substitute π = 22/7,

➙ 21 × (22/7) cm²

➙ 3 × 22 cm²

➙ 66 cm²

∴ Area of the shaded portion is 66 cm²