Copy of ACCESS - Secants and Tangents

Secant -Tangent Relationship

AP is a secant. CP is a tangent. AP and CP intersect outside of circle O. Move any of points A, B or C to change the lengths and take note of which values are the same. You may also move the slider r to change the length of the radius. Which products are always the same? How does the tangent length relate to the secant's length?