Triangle Exterior Angle Theorem

Front

What is the Triangle Exterior Angle Theorem?

Back

The Triangle 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 A is 40° and angle B is 60°, what is the measure of the exterior angle C?

Back

The measure of exterior angle C is 100° (40° + 60°).

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 remote interior angles.

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, and it is supplementary to the adjacent interior angle.

Front

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

Back

The remote interior angles are the angles that are not adjacent to angle d.

Front

Solve for x if angle A = 50° and angle B = 70°. What is the measure of the exterior angle?

Back

x = 120° (50° + 70°).

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°.

Front

If angle a = 30° and angle b = 50°, what is the measure of angle c?

Back

Angle c = 100° (180° - (30° + 50°)).

Front

What is the measure of angle b if angle a = 36° and angle c = 64°?

Back

Angle b = 80° (180° - (36° + 64°)).