Circles - Secants, Tangents and Angles

Front

What is a secant in relation to a circle?

Back

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

Front

Define a tangent line to a circle.

Back

A tangent line is a line that touches a circle at exactly one point.

Front

What is the relationship between the angles formed by a tangent and a chord through the point of contact?

Back

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

Front

State the Inscribed Angle Theorem.

Back

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

Front

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

Back

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

Front

How do you find the length of a tangent segment from a point outside the circle?

Back

The length of the tangent segment is 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 formula for the area of a circle?

Back

The area of a circle is A = πr², where r is the radius.

Front

How do you calculate the circumference of a circle?

Back

The circumference of a circle is C = 2πr, where r is the radius.

Front

What is the relationship between the angles in an inscribed quadrilateral?

Back

The opposite angles of an inscribed quadrilateral are supplementary (add up to 180°).

Front

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

Back

The measure of each angle is equal to half the sum of the measures of the arcs intercepted by the angle and its vertical angle.