Question

A circle is centered at the point (-3, 2) and passes through the point (1, 5). The radius of the circle is

Answer 1

`r =5`

Explanation:

Given

`(h,k) = (-3,2)` -- center

`(x,y) = (1,5)` --- pass through

Required

The radius (r)

The equation of circle is:

`(x - h)^2 + (y - k)^2 = r^2`

So, we have:

`(1 - -3)^2 + (5 - 2)^2 = r^2`

`(4)^2 + (3)^2 = r^2`

`16+9 = r^2`

`25 = r^2`

Take square roots of both sides

`5 = r`

`r =5`