9.2+Tangents+to+Circles


 * Secants and Tangents:** A **secant** to a circle is a line that intersects the circle at two points. A **tangent** is a line in the plane of the circle that intercets the circle at exactly one point, which is known as the **point of tangency**


 * Tangent Theorem:** If a line is tangent to a circle, then the line is perpendicular to a radius of the circle drawn to the point of tangency.


 * Radius and Chord Theorem:** A radius that is perpendicular to a chord of a circle bisects the chord.


 * Converse of the Tangent Theorem:** If a line is perpendiclar to a radius of a circle at its endpoints on the circle, then the line is tangent to the circle
 * Theorem:** The perpendicular bisector of a chord passes through the center of the circle.