Question

The sum of the areas of two circles is 80n square meters. Find the length of a radius of each circle if

one of them is twice as long as the other.
27
GO
What is the radius of the larger circle?

Answer 1

8 meters.

Explanation:

Let the 2 radii be x and 2x, then
π x^2 + π (2x)^2 = 80π

π x^2 + π 4x^2= 80π

x^2 + 4x^2= 80

5x^2 = 80

x^2 = 16

x = 4.

So the radius of the larger circle = 2*4 = 8 m.