Tangents, Radii, and Angles in Circles Review

Front

What is the measure of angle formed by two tangents that meet at an external point?

Back

The measure of the angle is equal to half the difference of the measures of the intercepted arcs.

Front

What is the relationship between two tangents drawn from a single external point to a circle?

Back

The two tangents are congruent to each other.

Front

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

Back

A line is tangent to a circle if it intersects the circle at exactly one point.

Front

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

Back

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

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 is equal to half the measure of the intercepted arc.

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.

Front

If two angles are formed by two tangents from an external point, how do you find the measure of one of the angles?

Back

The measure of one angle is equal to half the difference of the measures of the arcs intercepted by the angles.

Front

What is the relationship between the angles formed by two secants that intersect outside a circle?

Back

The measure of the angle is equal to half the difference of the measures of the intercepted arcs.

Front

What is the formula for finding the length of a tangent segment from a point outside the circle?

Back

The length of the tangent segment is equal to the square root of the difference between the square of the distance from the point to the center and the square of the radius.

Front

What is the significance of the radius in relation to a tangent line?

Back

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