Question

The ratio of diametre of two circle is 4:5. Find out ratio of their areas.​

Answer 1

Given Diametres Ratio 4:5

We Know the Area Of The Circle Πr²

A1:A2=Πr1:Πr2

22÷7×2=22÷7×(2.5)²

2:(2.5)²

Answer 2

Answer:

4 : 6.25

Step-by-step explanation:

let diameter of first circle is 4x & that of second circle is 5x.

hence radius of first circle is 2x and that of second circle is 2.5x.

area of first circle = pi r ^2

=22/7×(2x)^2=22/7×4x^2

area of second circle = pi r ^2

=22/7×(2.5x)^2=22/7×6.25x^2

hence ratio of their areas=

22/7×4x^2 :22/7×6.25x^2

=4:6.25