Question

7. The circumference of a circle in centimetres is the same number of units as its area in square centimetres. What is the radius of the circle?​

Answer 1

Answer: 2 cm

Explanation:

We can set up an equation using the given formula for the circumference of a circle and the area of a circle to solve for the radius (r).

Given:

2πr = πr²

Move terms to one side:

0 = πr² - 2πr

πr² - 2πr = 0

Factor:

r(πr - 2π) = 0

Set factors equal to 0:

πr - 2π = 0 r = 0

Solve unsolved factor:

πr - 2π = 0

πr = 2π

r = 2

The radius cannot be 0, so the radius is 2.