Question

the circumference of two circles are in ratio 11 : 13. find the ratio of areas.​

Answer 1

Step-by-step explanation:

we denote,

circumference of 1st circle C1

circumference of 2nd circle C2

C1 / C2 = 11/13

by formula of circumference of circle = (2 pi r)

2 pi r1 / 2 pi r2 = 11/13

r1 / r2 = 11/13

Area of circle = pi r^2

area of 1st circle A1 = pi r1^2

area of 2nd circle A2 = pi r2^2

A1/A2 = pi r1^2 / pi r2^2

= r1 ^2 / r2^2

= 11^2 / 13^2

A1/A2 = 121 / 169