Exterior Angle Theorem

Front

What is the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles.

Front

What are remote interior angles?

Back

Remote interior angles are the two angles inside a triangle that are not adjacent to a given exterior angle.

Front

If one exterior angle measures 120°, what is the sum of the remote interior angles?

Back

The sum of the remote interior angles is 120°.

Front

How do you find the measure of an unknown angle using the Exterior Angle Theorem?

Back

To find the measure of an unknown angle, add the measures of the two remote interior angles.

Front

What is the relationship between an exterior angle and its adjacent interior angle?

Back

The exterior angle and its adjacent interior angle are supplementary, meaning they add up to 180°.

Front

If Angle W is an exterior angle, what are the remote interior angles?

Back

The remote interior angles are the two angles inside the triangle that do not share a vertex with Angle W.

Front

Calculate the measure of x if the remote interior angles are 70° and 50°.

Back

x = 70° + 50° = 120°.

Front

What is the measure of an exterior angle if the remote interior angles are 40° and 60°?

Back

The measure of the exterior angle is 40° + 60° = 100°.

Front

If Angle A = 30° and Angle B = 50°, what is the measure of the exterior angle formed at Angle C?

Back

The measure of the exterior angle at Angle C is 30° + 50° = 80°.

Front

What is the sum of the measures of all angles in a triangle?

Back

The sum of the measures of all angles in a triangle is always 180°.