Triangle Sum Theorem and Exterior Angle Theorem Check-point

Front

What does the Triangle Sum Theorem state?

Back

The Triangle Sum Theorem states that the sum of all angles in a triangle is 180°.

Front

If one angle of a triangle is 30° and another is 60°, what is the measure of the third angle?

Back

The third angle is 90° (180° - 30° - 60°).

Front

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

Back

Each angle in an equilateral triangle measures 60°.

Front

What is the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

If one exterior angle of a triangle measures 120°, what is the sum of the two non-adjacent interior angles?

Back

The sum of the two non-adjacent interior angles is 120°.

Front

In a triangle, if two angles measure 45° and 55°, what is the measure of the third angle?

Back

The third angle measures 80° (180° - 45° - 55°).

Front

What is the relationship between the angles of a triangle and a straight line?

Back

The angles of a triangle and a straight line sum to 180°.

Front

If a triangle has angles measuring 70° and 40°, what is the measure of the third angle?

Back

The third angle measures 70° (180° - 70° - 40°).

Front

What is the measure of an angle that is supplementary to a 65° angle?

Back

The supplementary angle measures 115° (180° - 65°).

Front

If one angle of a triangle is 25° and the other two angles are equal, what are the measures of the other two angles?

Back

The other two angles each measure 77.5° (180° - 25° = 155°, then 155°/2 = 77.5°).