Tangent Lines (P1)

Drag the green dots to see more examples of the definitions related to circles and their tangent lines.
A TANGENT LINE is a line in the plane of the circle that intersects the circle in exactly one point.
The POINT OF TANGENCY is the point where a circle and a tangent intersect.
A TANGENT-CHORD ANGLE is an angle formed by an intersecting tangent and chord has its vertex “on”; the circle.
A) What is a tangent line?[br][br]B) What are two important parts of a tangent line and the circle it is tangent to?