Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet or intersect. 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 perpendicular lines are negative reciprocals of each other.

Front

If two lines have slopes m1 and m2, what condition must be met for them to be perpendicular?

Back

m1 * m2 = -1.

Front

What is the slope of a line parallel to y = 4x + 1?

Back

The slope is 4.

Front

What is the slope of a line perpendicular to y = -3x + 5?

Back

The slope is 1/3.

Front

Given the equations y = 2x + 3 and y = 2x - 1, what can be said about these lines?

Back

They are parallel.

Front

Given the equations y = 1/2x + 4 and y = -2x + 1, what can be said about these lines?

Back

They are perpendicular.

Front

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

Back

The slope is -5.

Front

If a line has a slope of 0, what type of line is it?

Back

It is a horizontal line.

Front

If a line has an undefined slope, what type of line is it?

Back

It is a vertical line.