Unit 11 Angle Relationships 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 drawn from the center of the circle to the circumference.

Front

What is the relationship between the angles formed by two intersecting chords in a circle?

Back

The measure of the 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 formula for finding the measure of an inscribed angle?

Back

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

Front

What is the relationship between the central angle and 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 definition of a tangent to a circle?

Back

A tangent to a circle is a line that touches the circle at exactly one point and is perpendicular to the radius at that point.

Front

What is the relationship between a tangent and a radius?

Back

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

Front

What is the formula for the measure of an angle formed by two tangents drawn 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 definition of a secant line?

Back

A secant line is a line that intersects a circle at two points.

Front

What is the relationship between the angles formed by a secant and a tangent?

Back

The measure of the angle formed by a secant and a tangent drawn from the same external point is equal to half the measure of the intercepted arc.

Front

What is the formula for the length of an arc?

Back

The length of an arc can be calculated using the formula: Length = (θ/360) * 2πr, where θ is the central angle in degrees and r is the radius.