Khan Academy Static

You know that a circle can be viewed as the set of all points that whose distance from the center is equal to the radius. In this tutorial, we use this information and the Pythagorean Theorem to derive the equation of a circle.

4012_Features_of_a_circle_from_its_expanded_equation.html

4011_Features_of_a_circle_from_its_standard_equation.html

4009_Pythagorean_theorem_radii_of_circles.html

4010_Standard_equation_of_a_circle.html