Triangle Sum and Exterior Angle Theorems

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 is 90 degrees, what are the measures of the other two angles?

Back

The other two angles must sum to 90 degrees, as the total must equal 180 degrees.

Front

What is an exterior angle of a triangle?

Back

An exterior angle 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 interior angle of a triangle is 50 degrees and another is 60 degrees, what is the third angle?

Back

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

Front

How do you find the measure of an exterior angle if the two non-adjacent interior angles are 30 degrees and 50 degrees?

Back

The exterior angle is 80 degrees (30 + 50 = 80).

Front

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

Back

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

Front

If a triangle has angles measuring 45 degrees and 45 degrees, what is the measure of the third angle?

Back

The third angle measures 90 degrees (180 - 45 - 45 = 90).

Front

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

Back

The formula is: Sum of angles = 180 degrees.

Front

If an exterior angle measures 120 degrees, what is the sum of the two non-adjacent interior angles?

Back

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