Tangents, Radii, and Angles in Circles Review

Front

What is a tangent to a circle?

Back

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

Front

How can you determine if a line is tangent to a circle?

Back

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

Front

What is the relationship between a tangent and a radius at the point of tangency?

Back

The tangent line is perpendicular to the radius at the point where the radius intersects the circle.

Front

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

Back

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

Front

What is the angle formed between two tangents drawn from an external point to a circle?

Back

The angle formed between two tangents drawn from an external point to a circle is equal to half the difference of the measures of the intercepted arcs.

Front

If two tangents are drawn from a point outside a circle, what can be said about their lengths?

Back

The lengths of the two tangents drawn from a point outside the circle to the circle are equal.

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 the average of the measures of the arcs intercepted by the angle and its vertical angle.

Front

How do you find the measure of an angle formed by a tangent and a secant?

Back

The measure of the angle formed by a tangent and a secant is equal to half the measure of the intercepted arc.

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 radius and the tangent line at the point of tangency?

Back

The radius drawn to the point of tangency is perpendicular to the tangent line.