Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

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

Front

What are perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees) and have slopes that are opposite reciprocals.

Front

How do you determine if two lines are parallel?

Back

Two lines are parallel if their slopes are equal.

Front

How do you determine if two lines are perpendicular?

Back

Two lines are perpendicular if the product of their slopes is -1.

Front

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

Back

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

Front

What is the slope of the line y = 3x + 2?

Back

The slope of the line y = 3x + 2 is 3.

Front

What is the equation of a line in slope-intercept form?

Back

The equation of a line in slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept.

Front

What does it mean for slopes to be opposite reciprocals?

Back

Slopes are opposite reciprocals if one slope is the negative reciprocal of the other, meaning if one slope is a/b, the other is -b/a.

Front

How do you write the equation of a line parallel to a given line?

Back

To write the equation of a line parallel to a given line, use the same slope as the given line and the point through which the new line passes.

Front

What is the point-slope form of a line?

Back

The point-slope form of a line is y - y1 = m(x - x1), where (x1, y1) is a point on the line and m is the slope.