Interior/Exterior Angles - 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

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

Back

It is a right triangle.

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.

Front

What is the relationship between an exterior angle and the two opposite interior angles?

Back

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

Front

If two angles of a triangle are 50 degrees and 80 degrees, what is the measure of the third angle?

Back

The third angle measures 50 degrees (180 - 50 - 80 = 50).

Front

What is the definition of an acute triangle?

Back

An acute triangle is a triangle where all three angles are less than 90 degrees.

Front

What is the definition of an obtuse triangle?

Back

An obtuse triangle is a triangle that has one angle greater than 90 degrees.

Front

How can you determine if three angles can form a triangle?

Back

The sum of the three angles must equal 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 a triangle has angles measuring 36 degrees and 63 degrees, what is the measure of the third angle?

Back

The third angle measures 81 degrees (180 - 36 - 63 = 81).