Solving for Angles

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 180°.

Front

What is the definition of complementary angles?

Back

Complementary angles are two angles whose measures add up to 90°.

Front

What is the definition of supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180°.

Front

If two angles are vertical angles, what can be said about their measures?

Back

Vertical angles are equal in measure.

Front

What is the relationship between the angles in a linear pair?

Back

Angles in a linear pair are supplementary, meaning they add up to 180°.

Front

In triangle ABC, if m∠A = 40° and m∠B = 60°, what is m∠C?

Back

m∠C = 80° (since 180° - 40° - 60° = 80°).

Front

What is the formula to find the measure of an exterior angle of a triangle?

Back

The measure of an exterior angle is equal to the sum of the measures of the two opposite interior angles.

Front

If m∠A = (3x + 10)° and m∠B = (2x + 20)°, find x if m∠C = 90°.

Back

x = 10 (since (3x + 10) + (2x + 20) + 90 = 180).

Front

What is the definition of an acute angle?

Back

An acute angle is an angle that measures less than 90°.

Front

What is the definition of an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90° but less than 180°.