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

Back

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

Front

What is the relationship between an exterior angle and its adjacent interior angle?

Back

The exterior angle is supplementary to its adjacent interior angle, meaning they add up to 180 degrees.

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

If angle a = 50° and angle b = 70°, what is the measure of the exterior angle d?

Back

The measure of exterior angle d is 50° + 70° = 120°.

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 W is an exterior angle, how do you identify its remote interior angles?

Back

Identify the two angles inside the triangle that do not share a vertex with angle W.

Front

What equation can be used to solve for x if x + 51 + 47 = 180?

Back

x = 180 - 51 - 47.

Front

If angle X = 30° and angle Y = 50°, what is the measure of angle W if it is the exterior angle?

Back

Angle W = 30° + 50° = 80°.