Question

Please Answer This

The area of two circles are in the ratio of 16:25. Find the ratio of their circumference.

Answer 1

Answer:

4:5

Step-by-step explanation:

ANSWER

Let the radii of the circles be r

1

& r

2

respectively.

Then, their circumferences are 2πr

1

& 2πr

2

, respectively.

So, their ratio=2πr

1

:2πr

2

=r

1

:r

2

.

Again, the areas of the circles are π(r

1

)

2

& π(r

2

)

2

.

Then, their ratio =π(r

1

)

2

:π(r

2

)

2

=(r

1

)

2

:(r

2

)

2

=16:25 ...(given).

∴(r

1

):(r

2

)=

16:25

=±(4:5)

We reject the negative value of r's since the radius is a length.

∴(r

1

):(r

2

)=(4:5).