Triangle Angle Sum

Front

What is the Triangle Angle Sum Theorem?

Back

The Triangle Angle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

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

Back

It is a right triangle.

Front

What is the measure of the third angle if two angles of a triangle are 50 degrees and 60 degrees?

Back

The third angle measures 70 degrees (180 - 50 - 60 = 70).

Front

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

Back

You can find the unknown angle by subtracting the sum of the known angles from 180 degrees.

Front

What is an exterior angle of a triangle?

Back

An exterior angle is formed by one side of the triangle and the extension of an adjacent side. The measure of an exterior angle is equal to the sum of the measures of the two opposite interior angles.

Front

If two angles of a triangle are equal, what type of triangle is it?

Back

It is an isosceles triangle.

Front

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

Back

In an equilateral triangle, all three angles are equal and each measures 60 degrees.

Front

How can you determine if a triangle is valid based on its angles?

Back

A triangle is valid if the sum of its angles is exactly 180 degrees.

Front

What is the formula to calculate the measure of an angle in a triangle if the other two angles are known?

Back

The formula is: Measure of the unknown angle = 180 - (Measure of angle 1 + Measure of angle 2).

Front

What is the significance of 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.