Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Lines that never intersect and have the same slope.

Front

What are perpendicular lines?

Back

Lines that intersect at a right angle (90 degrees) and have slopes that are opposite reciprocals.

Front

If two lines have slopes of 2 and -1/2, what can we say about them?

Back

They are perpendicular.

Front

What is the slope of a line parallel to the line with slope 3?

Back

3 (the slopes of parallel lines are identical).

Front

What is the slope of a line perpendicular to the line with slope -4?

Back

1/4 (the slope is the opposite reciprocal).

Front

If the slope of one line is 0, what can we say about a line perpendicular to it?

Back

It has an undefined slope (it is vertical).

Front

What is the relationship between the slopes of two parallel lines?

Back

They are identical.

Front

What is the relationship between the slopes of two perpendicular lines?

Back

They are opposite reciprocals.

Front

If line A has a slope of 1/3, what is the slope of a line perpendicular to it?

Back

-3 (the opposite reciprocal of 1/3).

Front

What is the slope of a line parallel to the line represented by the equation y = -5x + 2?

Back

-5 (the slope is the same).