Triangle Sum and Exterior Angle Theorems

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

If one angle of a triangle is 90 degrees, what type of triangle is it?

Back

It is a right triangle.

Front

What are the remote interior angles of an exterior angle in a triangle?

Back

The remote interior angles are the two angles in the triangle that are not adjacent to the exterior angle.

Front

How do you find the measure of an exterior angle of a triangle?

Back

The measure of an exterior angle is equal to the sum of the measures of the two remote interior angles.

Front

If angle A = 30° and angle B = 60°, what is angle C in triangle ABC?

Back

Angle C = 90° (since 30° + 60° + C = 180°).

Front

What is the measure of an angle that is supplementary to a 120° angle?

Back

The supplementary angle is 60° (180° - 120° = 60°).

Front

If angle W is 40°, what are the measures of the remote interior angles?

Back

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

Front

What is the relationship between the angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

If angle X = 45° and angle Y = 45°, what is angle Z in triangle XYZ?

Back

Angle Z = 90° (since 45° + 45° + Z = 180°).

Front

What is the definition of an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.