angles in circles

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, and the sides of the angle are formed by the chords.

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 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 tangent line to a circle?

Back

A tangent line is a straight line that touches the circle at exactly one point and does not cross into the circle.

Front

How do you find the measure of an angle formed by two tangents from a point outside the circle?

Back

The measure of the angle formed by two tangents drawn from a point outside the circle is equal to half the difference of the measures of the intercepted arcs.

Front

What is the measure of an angle formed by a tangent and a chord?

Back

The measure of the angle formed by a tangent and a chord through the point of contact is equal to half the measure of the intercepted arc.

Front

What is the sum of the angles in a circle?

Back

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

Front

If two chords intersect inside a circle, how do you find the measure of the angles formed?

Back

The measure of each 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

What is the measure of an angle formed by two secants that intersect outside the circle?

Back

The measure of the angle formed by two secants that intersect outside the circle is equal to half the difference of the measures of the intercepted arcs.

Front

What is the inscribed angle theorem?

Back

The inscribed angle theorem states that an inscribed angle is half the measure of the central angle that subtends the same arc.