Inside, Central, Inscribed Angles

Front

What is an inscribed angle?

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 relationship between an inscribed angle and the arc it intercepts?

Back

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

Front

What is a central angle?

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 circle.

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 intercepted arc.

Front

If angle A is an inscribed angle that intercepts arc BC, what is the measure of angle A if arc BC measures 80°?

Back

Angle A measures 40°.

Front

What is the measure of an angle formed by two tangents drawn from a point outside a circle?

Back

The measure of the angle formed by two tangents is equal to half the difference of the measures of the intercepted arcs.

Front

If a diameter of a circle is one side of an inscribed angle, what is the measure of that angle?

Back

The inscribed angle is a right angle (90°).

Front

What is the measure of angle 1 if it intercepts an arc measuring 130°?

Back

Angle 1 measures 65°.

Front

If angle LMO is a central angle and segment LO is a diameter, what is m∠LMO?

Back

m∠LMO is 90°.

Front

Which number best represents an inscribed angle if it intercepts an arc of 180°?

Back

The inscribed angle would measure 90°.