Complete the steps to derive the standard form of the equation of a circle centered at A(h, k).

✓ 1. What is segment AB to circle A? a chord a diameter a radius

✓ 2. The length of leg AC is x − h y − k h − k .

✓ 3. The length of leg BC is x − h y − k h − k .

✓ 4. Because △ABC is a right triangle, the Pythagorean theorem can be applied.
x x − h ² + y y − k ²  = r²