Two circles have areas of 16 (pi) and 25 (pi). Find the ratio of their circumferences.

Area of the first circle = 16 (pi)

We know that

Area of a circle = (pi) * (Radius) ^2

Then

16 (pi) = (pi) * (radius) ^2

(4) ^2 = (Radius) ^2

Radius = 4

Diameter = 8

Circumference = (pi) * Diameter

= 8 (pi)

In case of the second circle

Area = (pi) * (Radius) ^2

25 (pi) = (pi) * (Radius) ^2

(5) ^2 = (Radius) ^2

Radius = 5

Diameter = 10

Circumference = 10 (pi)

So

Circumference of first circle:Circumference of second circle = 8 (pi) : 10 (pi)

= 4:5