Interior and Exterior Angles of Triangles

Front

What is an interior angle of a triangle?

Back

An interior angle is formed by two sides of a triangle that meet at a vertex, and it is located inside the triangle.

Front

What is an exterior angle of a triangle?

Back

An exterior angle is formed by one side of a triangle and the extension of an adjacent side. It is located outside 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

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 obtuse triangle?

Back

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

Front

How do you find the measure of an exterior angle?

Back

The measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

If angle A is 50 degrees and angle B is 60 degrees, what is angle C in triangle ABC?

Back

Angle C is 70 degrees (180 - 50 - 60 = 70).

Front

What is the relationship between interior and exterior angles at a vertex?

Back

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

Front

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

Back

Each interior angle in an equilateral triangle measures 60 degrees.

Front

If the exterior angle is 120 degrees, what is the measure of the adjacent interior angle?

Back

The adjacent interior angle is 60 degrees (180 - 120 = 60).