Central and Inscribed Angles Review

Front

What is a central angle in a circle?

Back

A central angle is an angle whose vertex is at the center of the circle and whose sides are radii that extend to the circumference.

Front

What is an inscribed angle in a circle?

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 calculate the measure of a central angle?

Back

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

Front

How do you calculate the measure of an inscribed angle?

Back

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

Front

What is the relationship between a central angle and an inscribed angle that intercept the same arc?

Back

The central angle is twice the measure of the inscribed angle.

Front

If the measure of arc JK is 120°, what is the measure of the central angle that intercepts arc JK?

Back

The measure of the central angle that intercepts arc JK is also 120°.

Front

If the measure of arc AB is 80°, what is the measure of the inscribed angle that intercepts arc AB?

Back

The measure of the inscribed angle that intercepts arc AB is 40°.

Front

What is the formula for finding 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) in degrees.

Front

What is the value of x if the inscribed angle measures 40°?

Back

If the inscribed angle measures 40°, then the value of x (the measure of the intercepted arc) is 80°.

Front

What is the measure of angle ACB if it intercepts an arc measuring 120°?

Back

The measure of angle ACB is 60° because it is an inscribed angle.