Question

If the ratio of diameter of two circles is 3:7. Find the ratio of their circumferences.​

Answer 1

Answer:

3:7

Explanation:

phi×d/phi×D

d=3x

D=7x

Answer 2

Answer:3:7

Explanation:

D1/D2=3:7

Divide by 2 on both side

D1/2/D2/2=3/2/7/2

R1/R2=3:7. (1)

2*22/7*R1/2*22/7*R2=3:7

R1/R2=3:7. (2)

From eqn (1),(2)

2*22/7*R1/2*22/7*R2=3:7. ANS