Question

A diameter of a circle has endpoints at (3, -8) and (-5, -2). Find the radius of the circle.

Answer 1

Answer: r = 5

Explanation:

Using Pythagoras we can find the length of the diameter

d^2 = (3 - -5)^2 + (-8 - -2)^2

= 8^2 + (-6)^2

= 64 + 36

= 100

This means d = 10 and r = 5