Interior/Exterior Angles of Triangles CW 9/28

Front

What is an interior angle of a triangle?

Back

An interior angle of a triangle is formed by two sides of the triangle and is located inside the triangle.

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

What is 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.

Front

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

Back

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

Front

If one interior angle of a triangle is 90 degrees, what are the measures of the other two angles?

Back

The other two angles must sum to 90 degrees, as the total must equal 180 degrees.

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

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

Back

In an isosceles triangle, the two base angles are equal, and the sum of all angles is 180 degrees.

Front

If two angles of a triangle are 50 degrees and 60 degrees, what is the measure of the third angle?

Back

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

Front

What is the formula to calculate the exterior angle of a triangle?

Back

The exterior angle = interior angle 1 + interior angle 2.