Videos and lessons to help High School students learn how to
identify and describe relationships among inscribed angles, radii,
and chords.

*Topics include* the relationship between central, inscribed, and
circumscribed angles; inscribed angles on a diameter are right
angles; the radius of a circle is perpendicular to the tangent
where the radius intersects the circle.

Common Core: HSG-C.A.2

Introduction to Circles

This video introduces the features of circles including secant, secant line, chord, diameter, radius, tangent line, and intersecting circles.

Inscribed and Central Angles

Showing that an inscribed angle is half of a central angle that subtends the same arc.

Introduction to inscribed and central angles with a few examples.

An angle inscribed in a circle has half the angle measure of the corresponding central angle. Drag the vertices on the circle to change the angles. When you make DAC the diameter, angle E would be 90 degrees.

Example with tangent and radius.

Tangent Lines to a Circle Example Problems

This video provides example problems of determining unknown values using the properties of a tangent line to a circle.

Inscribed and Circumscribed Polygons.

Rotate to landscape screen format on a mobile phone or small tablet to use the **Mathway** widget, a free math problem solver that **answers your questions with step-by-step explanations**.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

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