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

Define remote interior angles in relation to an exterior angle.

Back

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

Front

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

Back

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

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 a = 30° and angle b = 50°, what is the measure of the exterior angle d?

Back

The measure of exterior angle d is 30° + 50° = 80°.

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, but it is not equal to the adjacent interior angle.

Front

If angle c is 70° and angle d is the exterior angle, what are the remote interior angles?

Back

The remote interior angles are the angles that are not adjacent to angle d, which are angle a and angle b.

Front

Solve for x if angle a = 40° and angle b = 60°, what is angle d?

Back

Angle d = 40° + 60° = 100°.

Front

What is the measure of angle b if angle d = 120° and angle a = 60°?

Back

Angle b = angle d - angle a = 120° - 60° = 60°.

Front

If angle a = 45° and angle b = 55°, what is the measure of angle d?

Back

Angle d = 45° + 55° = 100°.