5.1 Angles of Triangles

Front

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

Back

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

Front

Classify the triangle with angles measuring 120°, 30°, and 30°.

Back

Obtuse triangle.

Front

If one angle of a triangle is 85° and another is 40°, what is the measure of the third angle?

Back

55°.

Front

What is the measure of the third angle in a triangle if the first angle is 79° and the second angle is 43°?

Back

58°.

Front

What type of triangle has all angles measuring less than 90°?

Back

Acute triangle.

Front

What type of triangle has one angle measuring more than 90°?

Back

Obtuse triangle.

Front

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

Back

180°.

Front

If a triangle has angles measuring 90°, 45°, and 45°, what type of triangle is it?

Back

Right triangle.

Front

What is an equiangular triangle?

Back

A triangle where all three angles are equal, each measuring 60°.

Front

If one angle of a triangle is 110°, what can you say about the other two angles?

Back

They must each be less than 70° since the sum of all angles is 180°.