Missing Angles in a Triangle

Front

What is the sum of the angles in a triangle?

Back

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

Front

If two angles in a triangle are 30° and 70°, what is the measure of the third angle?

Back

80°

Front

What is a missing angle in a triangle?

Back

A missing angle in a triangle is the angle that, when added to the other two angles, equals 180°.

Front

Which of the following sets of angles can form a triangle? 1) 120°, 50°, 20° 2) 100°, 200°, 60° 3) 30°, 50°, 80° 4) 40°, 50°, 90°

Back

Only set 4 (40°, 50°, 90°) can form a triangle.

Front

How do you find a missing angle in a triangle?

Back

Subtract the sum of the known angles from 180°.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90°.

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90°.

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90° but less than 180°.

Front

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

Back

It is a right triangle.

Front

What is the relationship between the angles in a triangle?

Back

The angles in a triangle are related such that their sum is always 180°.