Interior and Exterior Angles of Triangles

Front

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

Back

180°

Front

What is an acute triangle?

Back

A triangle where all angles are less than 90°.

Front

What is an obtuse triangle?

Back

A triangle that has one angle greater than 90°.

Front

What is a right triangle?

Back

A triangle that has one angle equal to 90°.

Front

What is the Triangle Sum Theorem?

Back

The theorem stating that the sum of the interior angles of a triangle is always 180°.

Front

If one angle of a triangle is 95°, what is the maximum possible measure of the other two angles?

Back

85° (the other two angles must sum to 85°).

Front

If two angles of a triangle are 45° and 45°, what is the measure of the third angle?

Back

90°.

Front

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

Back

60°.

Front

If the angles of a triangle are in the ratio 2:3:4, what are the measures of the angles?

Back

40°, 60°, and 80°.

Front

What is the exterior angle theorem?

Back

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