10.4: Angles formed by Secants and Tangents
Obj: ________________________________________________
Vertex is ON the circle
• 1) 2)
Vertex is INSIDE the circle
• 1)
Vertex is OUTSIDE the circle
• 1) 2)
3)
Theorem• If a tangent and a secant (or a chord) intersect
on a circle at the point of tangency, then the measure of the angle formed is __________ the measure of its intercepted arc.
Ex:
Theorem
• The measure of an angle formed by two secants or chords intersecting in the interior of a circle is _______________ the ______________ of the measures of the intercepted arcs.
• The measure of an angle formed by two secants in the exterior of a circle is __________ the measures of the intercepted arcs.
• The measure of a secant-tangent angle with its vertex outside the circle is ____________
_____________________________________
• The measure of a tangent-tangent angle with • its vertex outside the circle is ____________• _____________________________________