Geometry Lesson: 10 – 5 Tangents Objective: Use properties of tangents. Solve problems involving circumscribed polygons.

Copy title & pic Tangents A line that is in the same plane as a circle that intersects the circle in exactly one point.

Copy title & pic Common Tangent A line, ray, or segment that is tangent to two circles in the same plane.

Copy each figure and draw the common tangents Copy each figure and draw the common tangents. If no common tangent exists, state no common tangent.

Copy each figure and draw the common tangents Copy each figure and draw the common tangents. If no common tangent exists, state no common tangent.

Copy title & pic Theorem 10.10

therefore segment KL is a tangent. Forms a right angle, therefore segment KL is a tangent.

Not a tangent.

Copy Use FOIL!

Theorem 10.11 Copy title & pic

Circumscribed Polygons A polygon is circumscribed about a circle if every side of the polygon is tangent to the circle.

Perimeter = 10 + 15 + 11 = 36 ft 8 3 3 7

Homework Pg. 721 2 – 26 E, 44 – 54 E