Triangle Angle Sum & Exterior Angle Theorem

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 Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

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

Back

The third angle is 80 degrees (180 - 45 - 55 = 80).

Front

What is the formula to find the measure of an exterior angle?

Back

The measure of an exterior angle is equal to the sum of the two opposite interior angles.

Front

In a triangle, if one angle measures 60 degrees, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles is 120 degrees (60 + 120 = 180).

Front

How do you find the missing angle in a triangle if you know the other two angles?

Back

Subtract the sum of the known angles from 180 degrees.

Front

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

Back

In an isosceles triangle, the angles opposite the equal sides are equal.

Front

If a triangle has angles measuring 30 degrees and 70 degrees, what is the measure of the third angle?

Back

The third angle measures 80 degrees (180 - 30 - 70 = 80).

Front

What is the sum of the angles in any triangle?

Back

The sum of the angles in any triangle is always 180 degrees.