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

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

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)

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

2 points of intersections

1 point of intersection (tangent circles)

Circles that share a center (concentric circles)

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

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

Theorem Tangent segments from a common external point are congruent

Examples classzone

Assignment Section 10-1 Page 655 Problems # 3-10, 12-14, 18-26 even