Circles
Equations
Example 2
Find an equation for the circle centered at (-5, 12) and passing through the point (-2, 8).
Step 1. Find the length of the radius.
In this example, the distance formula is needed to determine the radius.
Step 2. Substitute the center and radius into the standard form of a circle and simplify.
(x - (-5))2 + (y - (12))2 = 52
(x + 5)2 + (y - 12)2 = 25