Interior angles in triangles

Front

What does the Triangle Sum Theorem state?

Back

The sum of all angles in a triangle is 180°.

Front

If one angle in a triangle measures 90°, what can be said about the other two angles?

Back

The other two angles must sum to 90°.

Front

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

Back

Each angle measures 60°.

Front

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

Back

Subtract the sum of the known angles from 180°.

Front

If two angles in a triangle are 45° and 55°, what is the measure of the third angle?

Back

The third angle measures 80°.

Front

What is the relationship between the angles in an isosceles triangle?

Back

The two base angles are equal.

Front

In a triangle, if one angle measures 30°, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles is 150° (if one is 120° and the other is 30°).

Front

What is the definition of a right triangle?

Back

A triangle that has one angle measuring 90°.

Front

If a triangle has angles measuring 70° and 40°, what type of triangle is it?

Back

It is an acute triangle, as all angles are less than 90°.

Front

What is the measure of the angles in a triangle if one angle is twice the measure of another and the third angle is 20°?

Back

The angles measure 20°, 40°, and 120°.