Triangle 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

If one angle of a triangle measures 90°, what type of triangle is it?

Back

It is a right triangle.

Front

What is the measure of each angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60°.

Front

What is the relationship between the angles in a triangle?

Back

The sum of the angles in a triangle is equal to 180°.

Front

If two angles of a triangle are known, how can you find the third angle?

Back

Subtract the sum of the known angles from 180°.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 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 a right angle?

Back

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

Front

In a triangle, if one angle measures 30°, what can you say about the other two angles?

Back

The other two angles must sum to 150°.

Front

What is the exterior angle theorem?

Back

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