Angles in Circles

Front

What is the definition of an angle in a circle?

Back

An angle in a circle is formed by two rays (sides of the angle) that share a common endpoint (the vertex) and are positioned at the center of the circle.

Front

What is the measure of a central angle?

Back

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

Front

What is an inscribed angle?

Back

An inscribed angle is formed by two chords in a circle which have a common endpoint. The measure of an inscribed angle is half the measure of the intercepted arc.

Front

How do you find the measure of an angle formed by two tangents?

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 relationship between angles formed by intersecting chords?

Back

The measure of an angle formed by two intersecting chords is equal to the average of the measures of the arcs intercepted by the angle and its vertical angle.

Front

What is the formula for the sum of angles in a circle?

Back

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

Front

What is the relationship between a tangent and a radius?

Back

A tangent to a circle is perpendicular to the radius drawn to the point of tangency.

Front

How do you calculate 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 measure of an angle formed by two secants?

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 definition of a cyclic quadrilateral?

Back

A cyclic quadrilateral is a four-sided figure where all vertices lie on the circumference of a circle.