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

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 d is an exterior angle, which angles can be added to find its measure?

Back

The measures of the two remote interior angles.

Front

Solve for x: 42 + 8x = 2 + 12x

Back

x = 3

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 = 40° and angle b = 60°, what is the measure of the exterior angle formed at angle c?

Back

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

Front

Which two angles are the remote interior angles to Angle W?

Back

Angle X and Angle Y.

Front

If angle d is 120°, what are the measures of the remote interior angles?

Back

The sum of the remote interior angles must be 120°.

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

Back

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