Triangle Sum Theorem

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 measures 90 degrees, what can you say about the other two angles?

Back

The other two angles must sum to 90 degrees, making the triangle a right triangle.

Front

What is the measure of a straight angle?

Back

A straight angle measures 180 degrees.

Front

If two angles of a triangle measure 34 degrees and 38 degrees, what is the measure of the third angle?

Back

The third angle measures 108 degrees.

Front

If m∠1 = 30°, what is m∠3 if m∠1 and m∠3 are equal?

Back

m∠3 = 30°.

Front

What is the relationship between the angles in a triangle?

Back

The angles in a triangle are related such that their sum is always 180 degrees.

Front

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

Back

Subtract the sum of the known angles from 180 degrees.

Front

What is an exterior angle of a triangle?

Back

An exterior angle is equal to the sum of the two opposite interior angles.

Front

If one angle of a triangle is 70 degrees and another is 60 degrees, what is the third angle?

Back

The third angle is 50 degrees.

Front

What is the measure of an angle that is complementary to a 45-degree angle?

Back

The complementary angle measures 45 degrees.