# Geometry/Circles/Tangents and Secants

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A **tangent** is a line in the same plane as a given circle that meets that circle in exactly one point. That point is called the **point of tangency**. A tangent cannot pass through a circle; if it does, it is classified as a **chord**. A **secant** is a line containing a chord.

A **common tangent** is a line tangent to two circles in the same plane. If the tangent does not intersect the line containing and connecting the centers of the circles, it is an **external tangent**. If it does, it is an **internal tangent**.

Two circles are tangent to one another if in a plane they intersect the same tangent in the same point.