Triangle Theorems

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of all angles in a triangle is 180°.

Front

What do the angles in a triangle add up to?

Back

The angles in a triangle add up to 180°.

Front

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

Back

In an equilateral triangle, each angle measures 60°.

Front

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

Back

It is a right triangle.

Front

What is the relationship between the angles in a triangle?

Back

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

Front

If two angles of a triangle are 50° and 60°, what is the measure of the third angle?

Back

The third angle measures 70°.

Front

What is an isosceles triangle?

Back

An isosceles triangle has at least two sides that are equal in length and the angles opposite those sides are equal.

Front

What is a scalene triangle?

Back

A scalene triangle has all sides of different lengths and all angles of different measures.

Front

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

Back

To find an unknown angle, subtract the sum of the known angles from 180°.

Front

If a triangle has angles measuring 45° and 45°, what is the measure of the third angle?

Back

The third angle measures 90°.