Find the equation of a circle using the formula (x-h)squared+(y-k)squared=r squared. Know that h and k represent the coordinates for the center, with h being the x value, k being the y value and r being the radius.Continue Reading
Determine what the coordinates are for the center and what the radius equals.
Plug the coordinates and the radius value into the equation by substituting the information in place of the corresponding variable.
If the center is negative, the negative sign in the equation becomes positive. If the center is positive, the sign in the equation stays the same.