1. 12-1 Tangent Lines

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

3. Theorem 12-1 If a line is tangent to a circle, then the line is perpendicular to the radius drawn to the point of tangency.

4. Theorem 12-2 If a line is perpendicular to the radius drawn to the point of tangency, then the line is tangent to the circle.

5. Theorem 12-3 Two segments tangent to a circle from a point outside the circle are congruent.

6. Example #1 Find x. 117˚ x˚x˚ 360-117-90-90=63˚

7. Example #2 Find the distance between the centers of the pulleys. 26.5 in. 9.3 in. 4.3 in. 5 2 + 26.5 2 = c 2 27.0 in

8. Today's Assignment WS 12-1