Question

the radius of two circles are in the ratio 5 is to 8 if the difference between the area is 351 pi square cm .
.find the area of the bigger circle .( take pi as 3.14)

Answer 1

Hi

Let the common factor be x.
Therefore, the radius of both the circles becomes 5x and 8x respectively.
Area of the first circle
= 22/7 * 5x *5x
=(22 * 25 x^2) /7

Area of the the other circle
= 22/7 *8x*8x
=( 22*64x^2) /7

By the problem,
22 x^2 (64- 25) =351 *22/7 *1/7
=> x^2 = 351cm^2/39
=>x^2 = 117cm^2/13
=>x^2 =9cm^2
=>x = 3 cm

Therefore, the radius of the first circle
=5 *3cm
= 15cm

The radius of the second circle
=8*3cm
= 24 cm

Hope this is of help.

Answer 2

Answer:

Hope it helps!