Triangle Sum and Exterior Angle Theorem Practice

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of all angles in a triangle is 180°.

Front

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

Back

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

Front

What is the measure of an exterior angle of a triangle?

Back

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

Front

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

Back

You can find the measure of an unknown angle by subtracting the sum of the known angles from 180°.

Front

What is the relationship between the angles of a triangle and its exterior angles?

Back

The exterior angle is equal to the sum of the two non-adjacent interior angles.

Front

If angle A is 45° and angle B is 55°, what is angle C?

Back

Angle C is 80° (180° - 45° - 55° = 80°).

Front

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

Back

The formula is: Angle A + Angle B + Angle C = 180°.

Front

What is the measure of an angle if its exterior angle is 120°?

Back

The measure of the interior angle is 60° (180° - 120° = 60°).

Front

In a triangle, if one angle is twice the size of another, and the third angle is 30°, what are the measures of the other two angles?

Back

Let the smaller angle be x. Then the angles are x, 2x, and 30°. Therefore, x + 2x + 30° = 180°, leading to x = 50° and 2x = 100°.

Front

What is the measure of an angle in a triangle if the other two angles are 30° and 60°?

Back

The measure of the third angle is 90° (180° - 30° - 60° = 90°).