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 45 degrees and 55 degrees?

Back

The third angle measures 80 degrees (180 - 45 - 55 = 80).

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

If one angle of a triangle is 36 degrees, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles is 144 degrees (180 - 36 = 144).

Front

Solve for x: If angle A = 2x + 10 and angle B = 3x - 20, and they are supplementary, what is x?

Back

x = 10.

Front

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

Back

In an isosceles triangle, the angles opposite the equal sides are equal.

Front

If a triangle has angles measuring 70 degrees and 50 degrees, what is the measure of the third angle?

Back

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