Triangle Angle-sum and Exterior Angle Theorem Review

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

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 one angle of a triangle measures 41°, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles is 139° (since 180° - 41° = 139°).

Front

How do you find the measure of an unknown angle in a triangle when two angles are known?

Back

To find the measure of an unknown angle, 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 measures 90°, and the sum of the other two angles is 90°.

Front

If angle A = 36° and angle B = 54°, what is the measure of angle C in triangle ABC?

Back

Angle C = 180° - (36° + 54°) = 90°.

Front

What is the formula to calculate the measure of an exterior angle?

Back

The measure of an exterior angle is calculated as the sum of the two opposite interior angles.

Front

In triangle XYZ, if angle X = 66° and angle Y = 45°, what is angle Z?

Back

Angle Z = 180° - (66° + 45°) = 69°.

Front

What is the significance of the angles in a triangle?

Back

The angles in a triangle determine its shape and can be used to classify the triangle as acute, right, or obtuse.

Front

How can you determine if a triangle is obtuse?

Back

A triangle is obtuse if one of its angles measures more than 90°.