Section 9-2 Tangents

1. Section 9-2Tangents

2. Tangent theorems If a line is tangent to a circle then the line is perpendicular to the radius drawn to the point of tangency.

3. Tangent theorems

4. Tangent theorems Cont. If a line in the plane of a circle is perpendicular to the radius at its outer endpoint, then the line is tangent to the circle.

5. Tangent Corollary Tangents to a circle from a point are congruent

6. Tangent Corollary cont.

7. Tangent terms and definitions When each side of a polygon is tangent to a circle: a. The polygon is circumscribed about the circle b. The circle is inscribed in the polygon

8. Tangent terms and definitions

9. Tangent terms and definitions cont.. • A line that is tangent to each of 2 coplanar circles is called a common tangent.

10. Tangent terms and definitions cont.. • internal tangent segments intersect the segment joining the centers.

11. Tangent terms and definitions cont.. • Externaltangent segments do not intersect the segment joining the centers.

12. Tangentterms and definitions cont.. • Tangent circles are coplanar circles that are tangent to the same line at the same point • Externally tangent circles do not share interior points • Internally tangent circles share interior points

13. Tangent terms and definitions cont..