Question

A mechanic has two pieces of sandpaper of different sizes. Each piece is in the shape of a circle. The radius of the larger circle is 4 times the radius of the smaller circle. The area of the larger circle is how many times the area of the smaller circle?

Answer 1

16 times

Explanation:

difference in area = area of bigger circle / area of smaller circle

Area of a circle = πr²

r = radius

imagine the radius of the smaller circle = 1

Area of circle in terms of π= π

radius of the bigger circle = 4 x 1 = 4

Area of bigger circle in terms of π = π4² = 16 π

16 π / π = 16 times