Question

Find the area of a ring whose outer and inner radii are 20 cm and 15 cm, respectively.

Answer 1

Given:

The  outer and inner radii of the ring are 20 cm and 15 cm

To find:

The area of the ring

Solution:

The outer radius of the ring is R = 20 cm

The inner radius of the ring is r = 15 cm

in the chapter of the mensuration the area of the ring is given by:

Area of the outer circle - Area of the inner circle

πR² - πr²

π(R²-r²)

π(R+r)(R-r)

now by putting the value of the radius we get:

$\frac{22}{7}(20+15)(20-15)$

$\frac{22}{7}.35.5$

22×5×5

550 cm²

Hence, The area of the ring is 550 cm²

Answer 2

Answer:

Your answer is 550 cm

hope it will be helpful to u