Central and Inscribed Angles

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 (rays) extend to the circumference, measuring the angle formed by two radii.

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 circumference of the circle.

Front

How is the measure of a central angle related to 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 XZ is 100 degrees, what is the measure of the central angle that intercepts it?

Back

The measure of the central angle that intercepts arc XZ is also 100 degrees.

Front

If an inscribed angle intercepts an arc measuring 80 degrees, what is the measure of the inscribed angle?

Back

The measure of the inscribed angle is 40 degrees.

Front

What is the formula for calculating the measure of an inscribed angle?

Back

The formula for calculating the measure of an inscribed angle is: m∠ = 1/2(m arc).

Front

What is the measure of arc JK if the inscribed angle that intercepts it measures 60 degrees?

Back

The measure of arc JK is 120 degrees.

Front

What is the relationship between two inscribed angles that intercept the same arc?

Back

The two inscribed angles that intercept the same arc are equal in measure.

Front

How do you find the measure of an arc if you know the central angle?

Back

The measure of the arc is equal to the measure of the central angle.