Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet. They have the same slope.

Front

What are perpendicular lines?

Back

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

Front

If two lines have the same slope, what can we say about them?

Back

They are parallel.

Front

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

Back

-1/3

Front

What is the slope of a line perpendicular to a line with a slope of 5/8?

Back

-8/5

Front

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

Back

1/2

Front

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

Back

The slopes of two parallel lines are equal.

Front

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

Back

The product of their slopes is -1.

Front

If the equation of a line is y = 2x + 3, what is the slope?

Back

2

Front

If two lines are represented by the equations y = 5/7x + 2 and y = 5/7x - 30, what can we conclude about them?

Back

They are parallel.