Question

The diameters of two silver discs are in the ratio of 2:3. what is the ratio of their areas​

Answer 1

Step-by-step explanation:

Given:-

The diameters of two silver discs are in the ratio of 2:3.

To find:-

what is the ratio of their areas?

Solution:-

Let the diameters of the two discs be

d1 and d2 units

d1=2r1 units

d2=2r2 units

Their ratio =2:3

=>d1:d2=2:3

=>2r1:2r2=2:3

=>2r1/2r2=2/3

=>r1/ r2=2/3

=>r1:r2=2:3

Let they be r1=2x and r2=3x

Area of the first disc

=Area of the circle

=πr1²

=>π(2x)²

=>4πx²------(1)

Area of the second disc

=>πr²2

=>π(3x)²

=>9πx²------(2)

Their ratio =4πx²:9πx²

=>4:9

Answer:-

Ratio of areaa of the two discs =4:9