Question

The points (-2,5) and (9,-3) are the endpoints of the diameter of a circle, how do you find the length of the radius of the circle?

Answer 1

Radius of circle `~= 6.80`

Explanation:

(see rough diagram below)
The diameter of the circle is given by the Pythagorean theorem as
`color(white)("XXX")sqrt(8^2+11^2)`

`color(white)("XXX")=sqrt(185`

`color(white)("XXX")~=13.60` (using calculator)

The radius is half the length of the diameter.