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

How do you find the measure of an exterior angle?

Back

To find the measure of an exterior angle, add the measures of the two non-adjacent (remote) interior angles.

Front

If Angle A is 24 degrees and Angle B is 31 degrees, what is the measure of the exterior angle adjacent to Angle C?

Back

The exterior angle is 24 + 31 = 55 degrees.

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 its 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

Solve for x: If Angle A = 24 degrees and Angle B = 31 degrees, what is x if x is the exterior angle?

Back

x = 24 + 31 = 55 degrees.

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, not the adjacent interior angle.

Front

If the measure of one remote interior angle is 40 degrees and the other is 60 degrees, what is the measure of the exterior angle?

Back

The exterior angle is 40 + 60 = 100 degrees.

Front

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

Back

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

Front

If Angle X is 50 degrees and Angle Y is 70 degrees, what is the measure of the exterior angle adjacent to Angle Z?

Back

The exterior angle is 50 + 70 = 120 degrees.