1. Use Properties of Tangents
Geometry Section 10-1
Use Properties of Tangents

2. Circle
Set of all points in a plane that are equidistant from a given point called the center
Radius segment whose endpoints are the center and any point on the circle
Chord a segment whose endpoints are on a circle
Diameter a chord that intersects the center of the circle

3. Circle Secant is a line that intersects a circle in two points
Tangent is a line, segment, or ray in the plane of a circle that intersects the circle in exactly one point (point of tangency)

5. Coplaner circles
Two circles can intersect in two points, one point or no points

6. 2 points of intersections

7. 1 point of intersection (tangent circles)

8. Circles that share a center (concentric circles)

9. Common Tangents
A line, ray, or segment that is tangent to two coplaner circles

10. Theorem
In a plane, a line is tangent to a circle if and only if the line is perpendicular to a radius of the circle at its endpoint on the circle

11. Theorem
Tangent segments from a common external point are congruent

12. Examples
classzone

13. Assignment
Section 10-1
Page 655
Problems # 3-10, 12-14, even