4.5.2 Angle Relationships in Triangles

Front

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

Back

The sum of the interior angles in 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

If two angles are complementary, what is the sum of their measures?

Back

The sum of the measures of two complementary angles is 90 degrees.

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

What does it mean for two triangles to be similar?

Back

Two triangles are similar if their corresponding angles are equal and their corresponding sides are in proportion.

Front

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

Back

To find the measure of an unknown angle in a triangle, subtract the sum of the known angles from 180 degrees.

Front

What is the definition of an acute angle?

Back

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

Front

What is the definition of an obtuse angle?

Back

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

Front

What is the definition of a right angle?

Back

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

Front

How can you determine if two angles are supplementary?

Back

Two angles are supplementary if the sum of their measures is 180 degrees.