1. 11-1 Tangent Lines Learning Target: I can solve and model problems using tangent lines. Goal 2.03

2. A tangent to a circle is a line in the plane of the circle that intersects the circle in exactly one point.

3. The point where a circle and a tangent intersect is the point of tangency.

4. Theorem 11-1 If a line is tangent to a circle, then the line is perpendicular to the radius drawn to the point of tangency. AB OP O A P B

5. Theorem 11-2 (Converse of thm. 11-1) If aline in the plane of a circle is perpendicular to a radius at its endpoint on the circle, then the line is tangent to the circle. O A P B

6. If all vertices of a triangle lie on the circle, the triangle is inscribed in the circle. If a circle is inscribed inside a triangle, the triangle is circumscribed about the circle.

7. Theorem 11-3 The two segments tangent to a circle from a point outisde the circle are congruent. AB ≅ CB O B C A