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12-4A Angle Measures and Segment Lengths. Secant A line that intersects a circle in exactly two points.
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SecantA line that intersects a circle in exactly two points.
Theorem 11-11 AIf two secants intersect in the interior of a circle, then the sum of the measures of the arcs intercepted by the angle and its vertical angle is twice the measure of the angle formed.
Th. 11-11 A 2(m 1) = m PB + m RL = R P 1 B L
Theorem 11-11 BIf two secants or tangents intersect outside a circle, then the difference of the measures of the intercepted arcs is twice the measure of the angle formed.
Th. 11-11 B 2(m RMS) = m AB – m RS A R M S B
Good for Cheat SheetOutside 2( ) = big arc – little arc On 2( ) = arc Inside 2( ) = arc in-front + arc behind