http://www.ck12.org Chapter 9. Circles
9.7 Angles On and Inside a Circle
Here you’ll learn how to solve problems containing angles that are on or inside a circle.
What if you were given a circle with either a chord and a tangent or two chords that meet at a common point? How
could you use the measure of the arc(s) formed by those circle parts to find the measure of the angles they make on
or inside the circle? After completing this Concept, you’ll be able to apply the Chord/Tangent Angle Theorem and
the Intersecting Chords Angle Theorem to solve problems like this one.
Watch This
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Click image to the left for more content.CK-12 Foundation: Chapter9AnglesOnandInsideaCircleA
Watch the second part of this video.
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Click image to the left for more content.Brightstorm:Chords to Tangents
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Click image to the left for more content.Brightstorm:Secants
Guidance
When an angle is on a circle, the vertex is on the circumference of the circle. One type of angle on
Investigation: The Measure of an Angle formed by a Tangent and a Chord
Tools Needed: pencil, paper, ruler, compass, protractor