Flashcard on Arcs, Inscribed and Central Angles

Front

What is a central angle?

Back

A central angle is an angle whose vertex is at the center of a circle and whose sides (rays) extend to the circumference of the circle.

Front

What is an inscribed angle?

Back

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

Front

How do you determine if an angle is a central angle, inscribed angle, or neither?

Back

To determine the type of angle, check the position of the vertex: if it is at the center of the circle, it is a central angle; if it is on the circle, it is an inscribed angle; otherwise, it is neither.

Front

What is the relationship between a central angle and the arc it intercepts?

Back

The measure of a central angle is equal to the measure of the arc it intercepts.

Front

What is the relationship between an inscribed angle and the arc it intercepts?

Back

The measure of an inscribed angle is half the measure of the arc it intercepts.

Front

If the measure of arc DC is 122 degrees, what is the measure of the inscribed angle that intercepts arc DC?

Back

The measure of the inscribed angle that intercepts arc DC is 61 degrees.

Front

What is the formula to find the measure of an arc in a circle?

Back

The measure of an arc can be found using the formula: Arc Measure = Central Angle Measure.

Front

How do you find the measure of an angle 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.

Front

What is the sum of the measures of angles around a point?

Back

The sum of the measures of angles around a point is 360 degrees.

Front

If angle ACB is a central angle measuring 72 degrees, what is the measure of arc AB?

Back

The measure of arc AB is also 72 degrees.