The sum of the areas of the two circles is 180pi square inches. The length of a radius of the smaller circle is 6 inches less than the length of a radius of the larger circle. .

Question

Find the length of a radius of each circle

Answer 1

Consider that youre adding two areas together. Area of Circle 1 and Area of Circle 2 which equals 180pi.

We know that area of a circle can be found using the formula A=pi*r*2, read as area equals pi, times radius squared.

Circle 1's Area = (pi * r^2) and Circle 2's Area = (pi * (r-6)*2) The radius of Circle 2 is r-6 as it is 6 inches less than the other radius we don't know yet.

(pi * r*2)+(pi * (r-6)*2) = 180pi

Solve for r! Keep both sides of the equation balanced as you get r by itself on one side, and your answer on the other!