Angle Relationships

Front

What type of angle is less than 90°?

Back

Acute angle

Front

What type of angle is exactly 90°?

Back

Right angle

Front

What type of angle is greater than 90° but less than 180°?

Back

Obtuse angle

Front

What type of angle is exactly 180°?

Back

Straight angle

Front

What is the sum of the angles in a triangle?

Back

180°

Front

What are two angles that add up to 90° called?

Back

Complementary angles

Front

What are two angles that add up to 180° called?

Back

Supplementary angles

Front

If one angle is 30°, what is its complementary angle?

Back

60°

Front

If one angle is 120°, what is its supplementary angle?

Back

60°

Front

What is the term for angles that are opposite each other when two lines cross?

Back

Vertical angles