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.

Tags

CCSS.8.G.A.5

Front

If one interior angle of a triangle is 40° and another is 60°, what is the measure of the exterior angle?

Back

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

Tags

CCSS.8.G.A.5

Front

What are remote interior angles?

Back

Remote interior angles are the two interior angles of a triangle that are not adjacent to a given exterior angle.

Tags

CCSS.8.G.A.5

Front

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

Back

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

Tags

CCSS.8.G.A.5

Front

Calculate the exterior angle if the remote interior angles are 50° and 70°.

Back

The exterior angle is 120° (50° + 70°).

Tags

CCSS.8.G.A.5

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.

Tags

CCSS.8.G.A.5

Front

If an exterior angle measures 130°, what is the sum of the remote interior angles?

Back

The sum of the remote interior angles is 130°.

Tags

CCSS.8.G.A.5

Front

In a triangle, if one angle is 90°, what can be said about the exterior angle?

Back

The exterior angle will be greater than 90° since it is equal to the sum of the other two angles.

Tags

CCSS.8.G.A.5

Front

What is the measure of an exterior angle if one remote interior angle is 45° and the other is 55°?

Back

The exterior angle measures 100° (45° + 55°).

Tags

CCSS.8.G.A.5

Front

If Angle X is 30° and Angle Y is 50°, what is the measure of the exterior angle adjacent to Angle Z?

Back

The exterior angle adjacent to Angle Z measures 80° (30° + 50°).

Tags

CCSS.8.G.A.5