Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet or intersect, no matter how far they are extended. They have the same slope.

Front

What are 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 the slope of a line is m, what is the slope of a line parallel to it?

Back

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

Front

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

Back

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

Front

Determine if the lines with slopes 3 and -1/3 are parallel, perpendicular, or neither.

Back

Perpendicular, because their slopes are negative reciprocals.

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Back

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Back

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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 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; they are simply different.