endpoints of a diameter of a circle

1/2 way between those endpoints is the center      (h,k) =  (   -1,-4 )

 The total distance between the points is the DIAMETER = sqrt 288

     1/2 of which is th radius = sqrt(72)

Circle form = 

 (x-h)^2 + (y-k)^2 = r^2

(x+1)^2 + (y+4)^2 = 72

Here's a graph:

https://www.desmos.com/calculator/0dkqbxgyxy

thank you!

I hope this helps, too.