Notes for the 15th

tangent to a circle- a tangent us a line that touches a circle in one spot.
point of tangency- the single point where that line touches the circle.


Tangent Theorem 10-9: 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.

Theorem 10-10: If a line is perpendicular to a radius of a circle at its endpoint on the circle, then hte line is a tangent to the circle

Theorem 10-11: If two segments from the same exterior point are tangent to a circle then they are congruent.