Interior and Exterior Angles of Triangles

Front

What is the sum of the interior angles of a triangle?

Back

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

Front

Define an exterior angle of a triangle.

Back

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

Back

It is a right triangle.

Front

What is the relationship between the interior and exterior angles of a triangle?

Back

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

Front

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

Back

Subtract the sum of the known angles from 180 degrees.

Front

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

Back

Each angle in an equilateral triangle measures 60 degrees.

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 measures 80 degrees.

Front

What is the formula for finding the exterior angle of a triangle?

Back

Exterior angle = Interior angle 1 + Interior angle 2.

Front

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

Back

The maximum possible measure of the other two angles is 150 degrees (since they must sum to 150 degrees to keep the total at 180 degrees).

Front

What type of triangle has all angles less than 90 degrees?

Back

It is an acute triangle.