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

Back

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

Front

How do you calculate the measure of an exterior angle?

Back

To calculate the measure of an exterior angle, add the measures of the two remote interior angles.

Front

If Angle X = 50° and Angle Y = 60°, what is the measure of the exterior angle W?

Back

The measure of exterior angle W is 110° (50° + 60°).

Front

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

Back

The exterior angle is equal to the sum of the two remote interior angles, while the adjacent interior angle is not included in this sum.

Front

If the measure of Angle W is 130°, what are the possible measures of the remote interior angles?

Back

The sum of the remote interior angles must equal 130°.

Front

What is the measure of an exterior angle if the remote interior angles are 40° and 70°?

Back

The measure of the exterior angle is 110° (40° + 70°).

Front

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

Back

The measure of exterior angle C is 80° (30° + 50°).

Front

What is the sum of the measures of the interior angles of a triangle?

Back

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