Angle Relationships and Triangles

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 an acute angle?

Back

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

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90°.

Front

What is an obtuse angle?

Back

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

What is the Triangle Inequality Theorem?

Back

The Triangle Inequality Theorem states that the sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Front

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

Back

To find the measure of a missing angle in a triangle, subtract the sum of the known angles from 180°.

Front

What are the properties of an equilateral triangle?

Back

An equilateral triangle has three equal sides and three equal angles, each measuring 60°.

Front

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

Back

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