Lines and Angles

Front

What is a right angle?

Back

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

Front

What is an acute angle?

Back

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

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

A straight angle is an angle that measures exactly 180 degrees.

Front

What are perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees).

Front

What are intersecting lines?

Back

Intersecting lines are lines that cross each other at any angle.

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet and are always the same distance apart.

Front

How do you identify a right angle in a diagram?

Back

A right angle is often marked with a small square in the corner of the angle.

Front

What is the sum of angles in a triangle?

Back

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

Front

What is the relationship between complementary angles?

Back

Complementary angles are two angles whose measures add up to 90 degrees.