Answer:
Step-by-step explanation:
The equation for a circle is
[tex](x-h)^2+(y-k)^2=r^2[/tex]
This should tell you that in order to write the equation for a circle, you need either the center and a point and then solve for the radius, or you need 2 points ON the circle that will help you find the center (it would be exactly between those 2 points so you could use the midpoint formula to find the center and then you would have the h and the k and can take it from there.)
The definition of a circle is the locus of all points that is equidistant from a point in space. That point in space is the center and all the points equidistance from it are ON the circle, not inside the circle.
Hope that helps.
