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.

Front

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

Back

Two lines are parallel if m1 = m2.

Front

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

Back

Two lines are perpendicular if m1 * m2 = -1.

Front

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

Back

The slope of a line perpendicular to a line with slope 4 is -1/4.

Front

What is the slope of a line perpendicular to a line with slope -2?

Back

The slope of a line perpendicular to a line with slope -2 is 1/2.

Front

Given the equations y = 2x + 3 and y = 2x - 5, are these lines parallel, perpendicular, or neither?

Back

These lines are parallel.

Front

Given the equations y = 1/2x + 1 and y = -2x + 3, are these lines parallel, perpendicular, or neither?

Back

These lines are perpendicular.

Front

What is the slope of the line represented by the equation y = -3x + 4?

Back

The slope of the line is -3.

Front

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

Back

The slope of the line is 5.