Question

The circumference of two circles are 62.8 m and 37.68 m. Find the area between the two circles.​

Answer 1

Outer circle has circumference =396cm and inner circle has circumference=374cm

Circumference of outer circle=2πr=396cm

⇒2×

7

22

r=396

∴r=

2

396

×

22

7

=63cm

Area of outer circle=πr

2

=

7

22

×63×63=12,474cm

2

Circumference of inner circle=2πr=374cm

⇒2×

7

22

r=374

∴r=

2

374

×

22

7

=59.5‬cm

Area of inner circle=πr

2

=

7

22

×59.5×59.5=3,540.25‬cm

2

∴ Area of the shaded region=Area of outer circle−Area of inner circle

=12,474cm

2

−3,540.25‬cm

2

=8,933.75‬‬cm

2