Basic Angles and Arcs of Circles

Front

What is an inscribed angle in a circle?

Back

An inscribed angle is formed by two chords in a circle which have a common endpoint. The vertex of the angle is on the circle, and the sides of the angle are the chords.

Front

What is the intercepted arc of an inscribed angle?

Back

The intercepted arc is the arc that lies in the interior of the inscribed angle and has endpoints on the angle.

Front

What is the measure of an inscribed angle in relation to its intercepted arc?

Back

The measure of an inscribed angle is half the measure of its intercepted arc.

Front

Define a major arc in a circle.

Back

A major arc is an arc that measures more than 180 degrees.

Front

Define a minor arc in a circle.

Back

A minor arc is an arc that measures less than 180 degrees.

Front

What is a semicircle?

Back

A semicircle is an arc that measures exactly 180 degrees.

Front

How do you determine the measure of a minor arc?

Back

The measure of a minor arc is equal to the measure of the central angle that subtends it.

Front

What is the relationship between the angles formed by two intersecting chords?

Back

The measure of the angle formed by two intersecting chords is equal to half the sum of the measures of the arcs intercepted by the angle and its vertical angle.

Front

If angle ABC measures 90 degrees, what can you say about the arcs it intercepts?

Back

Angle ABC intercepts arcs that together measure 180 degrees.

Front

How do you find the measure of a major arc if you know the measure of the minor arc?

Back

The measure of a major arc can be found by subtracting the measure of the minor arc from 360 degrees.