5.1 Angles of Triangles

Front

What is the exterior angle of a triangle equal to?

Back

The sum of the two opposite interior angles.

Front

Classify a triangle with angles measuring 30°, 60°, and 90°.

Back

Right triangle.

Front

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

Back

180°.

Front

If one angle of a triangle is 100°, what can you say about the other two angles?

Back

They must each be less than 80°.

Front

What type of triangle has all sides of equal length?

Back

Equilateral triangle.

Front

What type of triangle has one angle greater than 90°?

Back

Obtuse triangle.

Front

What is the measure of the third angle in a triangle if the first two angles are 45° and 45°?

Back

90°.

Front

Classify a triangle with angles measuring 50°, 60°, and 70°.

Back

Acute triangle.

Front

What is an isosceles triangle?

Back

A triangle with at least two sides of equal length.

Front

What is a scalene triangle?

Back

A triangle with all sides of different lengths.