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 an exterior angle of a triangle?

Back

An exterior angle of a triangle is formed by one side of the triangle and the extension of an adjacent side.

Front

State 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 angle of a triangle is 90 degrees, what can you say about the other two angles?

Back

The other two angles must add up to 90 degrees, since the sum of all angles in a triangle is 180 degrees.

Front

What is the measure of the third angle if two angles of a triangle are 50 degrees and 60 degrees?

Back

The third angle measures 70 degrees (180 - 50 - 60 = 70).

Front

True or False: The angles of a triangle can be greater than 180 degrees.

Back

False. The angles of a triangle always add up to exactly 180 degrees.

Front

What is the relationship between the angles of an equilateral triangle?

Back

In an equilateral triangle, all three angles are equal and each measures 60 degrees.

Front

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

Back

To find an unknown angle, subtract the sum of the known angles from 180 degrees.

Front

If one angle of a triangle is 30 degrees and the other is 70 degrees, what is the measure of the third angle?

Back

The third angle is 80 degrees (180 - 30 - 70 = 80).

Front

What is the sum of the angles in a triangle?

Back

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