Question

The area of ring in sq.Cm whose inner radius 3.5cms and outer radius 10.5cms is

Answer 1

Answer:

308 m²

Step-by-step explanation:

Area of the circle = πr²

Area of the outer circle = π(10.5)² = 110.25π cm²

Area of the inner circle =  π(3.5)² = 12.25π cm²

Area of the ring = 110.25π - 12.25π  = 98π = 308 m²

Answer: The area of the ring is 308 m²

Answer 2

Given:

Inner radius = 3.5 cm

Outer radius = 10.5 cm

To find:

Area

Solution:

Area  = π ( radius )^2

Substituting,

Area of the outer ring= π ( 10.5 )^2

π * 10.5 *10.5

Area of the outer ring = 110.25 π sq.cm

Area of the inner ring =  π ( 3.5 )^2

π  * 3.5 * 3.5

Area of the inner ring =  12.25 π sq.cm

Area of the ring = Area of the outer ring - Area of the inner ring

110.25π - 12.25π

98π 

98 * 3.14

Area of the ring = 307.845 sq.cm