Triangle Angle Sum Theorem & Exterior Angle Theorem

Front

What is the Triangle Angle Sum Theorem?

Back

The Triangle Angle 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 50° and another is 60°, what is the measure of the third angle?

Back

70°

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 non-adjacent interior angles.

Front

If an exterior angle measures 120°, and one of the non-adjacent interior angles is 50°, what is the measure of the other non-adjacent interior angle?

Back

70°

Front

What is the measure of each angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60°.

Front

How do you find the measure of an angle in a triangle if you know the measures of the other two angles?

Back

Subtract the sum of the known angles from 180°.

Front

What is the relationship between the angles in a right triangle?

Back

In a right triangle, one angle is 90°, and the sum of the other two angles is 90°.

Front

If angle A is 40° and angle B is 50°, what is angle C in a triangle?

Back

Angle C is 90°.

Front

What is the formula to calculate the sum of angles in a polygon?

Back

The sum of the interior angles of a polygon with n sides is (n-2) × 180°.

Front

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

Back

60°.