Angles Formed By Lines Intersecting a Circle
Angles Formed By Lines Intersecting a Circle
1.Angles formed by two secants which intersect outside the circle : The measure of such an angle is equal to one-half the difference of
the arcs intercepted by the secants
2.Angles formed by a tangent and a chord : This angle is one-half arc it cuts off
3.Angles formed by two chords: The angle formed by two chords is one-half the sum of the intercepted arcs
Red dots are movable
Reference
1. The Art of the Problem Solving by Sandor Lehoczky and Richard Rusczyk
228 2015