Triangles: Classifying, Triangle Sum, & Triangle Inequality

Front

What is an acute triangle?

Back

A triangle where all three angles are less than 90 degrees.

Front

What is an obtuse triangle?

Back

A triangle that has one angle greater than 90 degrees.

Front

What is a right triangle?

Back

A triangle that has one angle equal to 90 degrees.

Front

What is an equilateral triangle?

Back

A triangle where all three sides are equal in length and all angles are equal to 60 degrees.

Front

What is an isosceles triangle?

Back

A triangle that has at least two sides of equal length.

Front

What is the Triangle Sum Theorem?

Back

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

Front

What is the Triangle Inequality Theorem?

Back

The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Front

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

Back

It is a right triangle.

Front

How do you classify a triangle with angles measuring 30°, 60°, and 90°?

Back

It is an acute triangle.

Front

What is the measure of the third angle if two angles of a triangle are 70° and 60°?

Back

The third angle measures 50°.