Question

The radii of two circles are in the ratio 2:5. What is
the ratio of their areas?

please answer​

Answer 1

Answer:

Step-by-step explanation:

Selina solutions

Grade 7

Biology

Mathematics

Physics

Chapters in CONCISE Mathematics - Middle School - 7

Exercises in Mensuration

Question 21

Q21) The radii of two circles are in the ratio 3 : 5, find the ratio between their circumferences.

Solution:

The ratio of the radii of the circles = 3:5

Radius of first circle = 3x

Radius of second circle = 5x

Circumference = 2\pi r2πr

=2\pi\times3x=6\pi x=2π×3x=6πx

circumference of second circle = 2\pi r2πr

= 2\pi\times5x=10\pi x2π×5x=10πx

Ratio between their circumference

= 6\pi x:10\pi x6πx:10πx

= 16:10

= 3:5