Question

A circular waterfall is surrounded by a brick wall. The radius of the inner wall is 35 inches. If the bricks are 5 inches wide, what scale factor was used to determine the radius of outer wall?​

Answer 1

8:7

Explanation:

A scale factor (SF) is the ratio of two corresponding side lengths in similar figures.

The two circles are the similar figures, and the SF is the ratio of their corresponding radii.

SF = outer radius/inner radius

= (35 + 5)/35

= 40/35

= 8/7

The scale factor is 8:7.