Secant-Secant Angles Interior Secant Angle – An angle formed when two secants intersect inside a circle. Theorem 10.13 A secant angle whose vertex is inside a circle is equal in measure to half the sum of the arcs intercepted by it and its vertical angle.

Find if and Answer: 138 Example 6-1d

Secant-Secant Angles Exterior Secant Angle – An angle formed when two secants intersect outside a circle. Theorem 10.14 A secant angle whose vertex is outside a circle is equal in measure to half the difference of its larger and smaller intercepted arcs.

Find x. Answer: 111 Example 6-3c

Tangent-Tangent Angles Tangent-Tangent Angle – An angle formed when two tangents intersect in the exterior of a circle. Theorem 10.14 A tangent-tangent angle whose vertex is outside a circle is equal in measure to half the difference of its larger and smaller intercepted arcs.

PARKS Two sides of a fence to be built around a circular garden in a park are shown. Use the figure to determine the measure of Answer: 75 Example 6-4c