Circles: Interior and Exterior Angles

Front

What is the relationship between angles A and C in a cyclic quadrilateral?

Back

Angles A and C are supplementary (m∠A + m∠C = 180°).

Front

What is the measure of an angle formed by a tangent and a secant intersecting outside a circle?

Back

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

Front

If EF is a diameter of a circle, what is the measure of angle EGF?

Back

Angle EGF is 90° because it is inscribed in a semicircle.

Front

What is the measure of arc RS if arc SQ = 84° and ∠RPS = 26°?

Back

Arc RS measures 136°.

Front

How do you calculate the measure of an angle formed by two intersecting chords inside a circle?

Back

The measure of the angle is half the sum of the measures of the intercepted arcs.

Front

What is the relationship between angles A and B in a cyclic quadrilateral?

Back

Angles A and B are also supplementary (m∠A + m∠B = 180°).

Front

What is the formula for finding the measure of an angle formed by two tangents drawn from a point outside the circle?

Back

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

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 half the sum of the measures of the arcs intercepted by the angle and its vertical angle.

Front

What is the measure of angle ABD if minor arc AC = 72° and minor arc CD = 132°?

Back

Angle ABD measures 30°.

Front

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

Back

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