# Graphing 23 - parallel and perpendicular lines 1

Taught by YourMathGal
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Part of video series
Meets NCTM Standards:
Lesson Summary:

This lesson on graphing lines explores the concepts of parallel and perpendicular lines in relation to their slopes. Parallel lines have the same slope but different y-intercepts, while perpendicular lines have slopes that are opposite reciprocals of each other, with the product of their slopes being negative one. Through examples and practice problems, viewers can learn how to determine if two lines are parallel or perpendicular without graphing them, as well as how to find the slope of a line parallel or perpendicular to a given line.

Lesson Description:

Covers parallel and perpendicular lines in relation to their slopes. This is part 23 of a series of videos about graphing lines.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

• How do you find the slope between two points using the slope formula?
• How do you write an equation for a line that has a slope of -3 and goes through (0, 10)?
• What are perpendicular lines in geometry?
• What is true about the slope of perpendicular lines?
• How can you determine if two lines are perpendicular?
• Why are slopes of perpendicular lines opposite reciprocals of each other?
• If two lines are perpendicular to each other, what do their slopes multiply to equal?
• How do you state the slope of the line perpendicular to the line y = -2/3x + 5?
• What is the slope of the line perpendicular to the line 5x + y = 8?
• Are the lines y = 3/5x + 11 and y = -5/3x - 2 perpendicular?
• Are the lines y = 5/6x + 4 and y = -5/6x + 1 perpendicular?
• What are parallel lines in geometry?
• What is true about the slope of parallel lines?
• How can you determine if two lines are parallel?
• Are the lines y = 2x - 4 and y = 2x + 3 parallel?
• Are the lines y = -1/2x and x + 2y = 8 parallel?
• Are the lines 2x + 3y = 7 and 2x - 3y = 5 parallel?
• How can you re-write an equation that is in standard form in slope-intercept form in order to find the slope of the line?
• How do you find the slope of a line parallel to a line passing through the points (6, -2) and (3, 7)?
• #### Staff Review

• Currently 4.0/5 Stars.
This lesson explains how to find the equation of a line that is parallel to the line that passes through two points and goes through a given point. It also explains that two parallel lines have the same slope, and how to determine if two lines are parallel by comparing their slopes by putting them in slope-intercept form. Finally, this lesson explains that perpendicular lines have opposite reciprocal slopes, and it goes through several example problems determining if two lines are perpendicular.