High School Math : How to find the equation of a circle

Example Questions

Example Question #93 : Coordinate Geometry

The center of a circle is  and its radius is . Which of the following could be the equation of the circle?

Explanation:

The general equation of a circle is , where the center of the circle is  and the radius is .

Thus, we plug the values given into the above equation to get

Example Question #92 : Coordinate Geometry

Which one of these equations accurately describes a circle with a center of and a radius of ?