Equation of a circle (standard form, completing the square)

What you'll learn

1. Write the equation of a circle in standard form (x - h)^2 + (y - k)^2 = r^2 given its center and radius
2. Identify the center (h, k) and radius r from a standard-form circle equation
3. Convert a circle equation from general form (x^2 + y^2 + Dx + Ey + F = 0) to standard form by completing the square
4. Graph a circle on the coordinate plane by plotting the center and using the radius

Prerequisites

• Midpoint and distance in the coordinate plane