Question

tell me the answer it is very necessary for me. ​

Answer 1

Answer :

3:5

Note :

• Circumference : The length of the boundary of a circle is called its circumference .
• Mathematically , the length of the circumference of the circle of radius r is given by ; C = 2πr
• Also , the area of the circle with radius r is given by ; A = πr²

Solution :

Here ,

It is given that , the radii of two circles are in ratio 3:5 .

Let the radius of 1st circle be r and that of 2nd circle be R .

Thus ,

r:R= 3:5

Now ,

Let the circumference of 1st circle be c and that of 2nd circle be C .

Thus ,

c = 2πr and C = 2πR

Now ,

=> c/C = 2πr/2πR

=> c/C = r/R

=> c:C = r:R

=> c:C = 3:5

Hence ,

The ratio of the circumferences to the two circles under consideration is 3:5 .