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

What is the relationship between an exterior angle and the two opposite interior angles?

Back

The measure of an exterior angle is equal to the sum of the measures of the two opposite 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 total must equal 180 degrees.

Front

True or False: Every triangle has angles that add up to 180 degrees.

Back

True.

Front

Solve for the unknown angle if one angle is 49 degrees and another is 58 degrees.

Back

The unknown angle is 73 degrees (180 - 49 - 58 = 73).

Front

Find the measure of angle A if angle B is 51 degrees and angle C is 41 degrees.

Back

Angle A is 88 degrees (180 - 51 - 41 = 88).

Front

What is the measure of angle a if angle b is 36 degrees and angle c is 63 degrees?

Back

Angle a is 81 degrees (180 - 36 - 63 = 81).

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 measure of an exterior angle if the two opposite interior angles are 35 degrees and 45 degrees?

Back

The exterior angle measures 80 degrees (35 + 45 = 80).