Parallel and Perpendicular Slopes

Front

What are the slopes of parallel lines?

Back

The slopes of parallel lines are identical.

Front

What are the slopes of perpendicular lines?

Back

The slopes of perpendicular lines are opposite reciprocals.

Front

If the slope of one line is m = -1/3, what is the slope of a line parallel to it?

Back

The slope of a line parallel to it is also m = -1/3.

Front

If the slope of one line is m = 4, what is the slope of a line perpendicular to it?

Back

The slope of a line perpendicular to it is m = -1/4.

Front

What does it mean for two slopes to be negative reciprocals?

Back

Two slopes are negative reciprocals if the product of the slopes is -1.

Front

Are the slopes 2 and -1/2 negative reciprocals?

Back

Yes, because 2 * -1/2 = -1.

Front

What is the relationship between the slopes of two lines that are neither parallel nor perpendicular?

Back

The slopes of two lines that are neither parallel nor perpendicular do not have a specific relationship.

Front

If two lines have slopes m1 and m2, when are they parallel?

Back

They are parallel if m1 = m2.

Front

If two lines have slopes m1 and m2, when are they perpendicular?

Back

They are perpendicular if m1 * m2 = -1.

Front

What is the slope of a line that is horizontal?

Back

The slope of a horizontal line is 0.