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 opposite reciprocals.

Front

If two lines have the same slope, what can we say about them?

Back

If two lines have the same slope, they are parallel.

Front

What is the slope of a line perpendicular to a line with a slope of 3?

Back

The slope of a line perpendicular to a line with a slope of 3 is -1/3.

Front

How do you determine if two lines are parallel from their equations?

Back

Two lines are parallel if their slopes are equal.

Front

How do you determine if two lines are perpendicular from their slopes?

Back

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

Front

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

Back

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

Front

What is the slope of the line y = -4x + 1?

Back

The slope of the line y = -4x + 1 is -4.

Front

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

Back

A line with a slope of 0 is a horizontal line.

Front

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

Back

A line with an undefined slope is a vertical line.