Triangle sum and Exterior Angle Theorem

Front

What is the Triangle Sum Theorem?

Back

The Triangle 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 can you say about the other two angles?

Back

The other two angles must sum to 90 degrees, making the triangle 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

How do you 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 degrees.

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

Can a triangle have two obtuse angles?

Back

No, a triangle cannot have two obtuse angles because the sum of the angles would exceed 180 degrees.

Front

What is the formula to calculate the sum of angles in a triangle?

Back

The formula is: Angle A + Angle B + Angle C = 180 degrees.

Front

If one angle of a triangle is 45 degrees and another is 55 degrees, what is the measure of the third angle?

Back

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

Front

What set of angles can form a triangle?

Back

The angles must be positive and their sum must equal 180 degrees.

Front

If the exterior angle of a triangle is 120 degrees, what is the sum of the two remote interior angles?

Back

The sum of the two remote interior angles is 120 degrees.