SOLUTION: Find an equation of the circle: (2,-5), (18,25)

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Question 538337: Find an equation of the circle: (2,-5), (18,25)
Answer by KMST(5396) About Me  (Show Source):
You can put this solution on YOUR website!
Your problem may have been
"Find an equation for the circle centered at (2,-5), that contains the point (18,25)."
I'll solve that.
According to Pythagoras, the radius (r) of that circle, squared, is

If a point (x,y) is in that circle, its distance to the center is also r, so according to Pythagoras,
%28x-2%29%5E2%2B%28y-%28-5%29%29%5E2=%28x-2%29%5E2%2B%28y%2B5%29%5E2=1156=34%5E2
An elegant form of the equation for that circle would be
%28x-2%29%5E2%2B%28y%2B5%29%5E2=34%5E2
No memorized formulas were abused in the solving of this problem.