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

Define 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 65°, what is the sum of the remote interior angles?

Back

The sum of the remote interior angles is also 65°.

Front

What is an exterior angle in the context of a triangle?

Back

An exterior angle is formed by one side of a triangle and the extension of an adjacent side.

Front

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

Back

The remote interior angles are the two angles inside the triangle that are not adjacent to Angle W.

Front

Solve for x: If Angle A = 37° and Angle B = 41°, what is the measure of the exterior angle?

Back

x = 78° (x = Angle A + Angle B).

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 an exterior angle measures 120°, what are the possible measures of the remote interior angles?

Back

The remote interior angles must sum to 120°.

Front

Identify the two remote interior angles if Angle X = 50° and Angle Y = 70° and Angle Z is the exterior angle. What is the measure of Angle Z?

Back

Angle Z = 120° (Angle Z = Angle X + Angle Y).

Front

What is the measure of an exterior angle if one remote interior angle is 30° and the other is 50°?

Back

The exterior angle measures 80° (30° + 50°).