Parallel and Perpendicular Lines

Front

What is the definition of parallel lines?

Back

Parallel lines are lines in a plane that never meet. They have the same slope but different y-intercepts.

Front

What is the definition of perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees). The slopes of two perpendicular lines are negative reciprocals of each other.

Front

If a line has a slope of 3, what is the slope of a line parallel to it?

Back

The slope of a line parallel to it is also 3.

Front

If a line has a slope of -2, what is the slope of a line perpendicular to it?

Back

Front

Back

Front

Back

Front

Back

The slope is 3.

Front

Back

The slope is -4.

Front

If two lines have slopes of 1 and -1, are they parallel, perpendicular, or neither?

Back

They are perpendicular.

Front

Back

The slope is 2.