Equations of Parallel and Perpendicular Lines

Name ______Module 4

Equations of Parallel and Perpendicular Lines

Learning Target: I can apply slope criteria for parallel and perpendicular lines and use them to solve geometric problems.

Opening Exercises

1. What is the slope of the line passing through the points A and B, as shown on the graph below?

2. Write the equation of the line graphed below.

Equations of Parallel and Perpendicular Lines

Essential Understanding: Parallel lines have equal slopes.

1. Determine the slope of each line to show that the lines are parallel.

2. Which equation represents a line parallel to the graph of 2x-4y=16?

(1) y=12x-5

(2) y=-12x+4

(3) y=-2x+6

(4) y=2x+8

3. Which equation represents a line parallel to the x-axis?

(1) x=5

(2) y=10

(3) x=13y

(4) y=5x+17

4. Write an equation of the line that passes through the point (4,2) that is parallel to the line whose equation is 3x+6y=12.

Essential Understanding: The slopes of perpendicular lines are negative reciprocals.

5. What is the slope of a line perpendicular to the line y=5x-4?

6. Write an equation of the line that passes through the point (4,2) that is perpendicular to the line whose equation is 3x+6y=12.

7. Find the distance between the point (0,0) and the line y=-x+4.

Essential Understanding: A dilation takes a line not passing through the center of the dilation to a parallel line, and leaves a line passing through the center unchanged.

A. Graph the equation on the line that passes through the points A(-4,8) and B(4,6).

B. What is the equation of the line passing through the points A and B, as shown on the graph above?

C. The line that passes through the points A and B is dilated by a scale factor of 12 and centered at the origin. What is the equation that represents the image of the line after the dilation?

Name ______Module 4

Equations of Parallel and Perpendicular Lines Problem Set

1. Which equation represents a line parallel to the y-axis?

(1) x=y

(2) x=4

(3) y=4

(4) y=x+4

2. Which equation represents a line that is parallel to the line y=3-2x?

(1) 4x+2y=5

(2) 2x+4y=1

(3) y=3-4x

(4) y=4x-2

3. The line y = 2x – 4 is dilated by a scale factor of 32 and centered at the origin. Which equation represents the image of the line after the dilation?

(1) y = 2x – 4

(2) y = 2x – 6

(3) y = 3x – 4

(4) y = 3x – 6

4. The equation of line h is 2x+y=1. Line m is the image of line h after a dilation of scale factor 4 with respect to the origin. What is the equation of the line m?

(1) y = –2x + 1

(2) y = –2x + 4

(3) y = 2x + 4

(4) y = 2x + 1

5. If the graphs of the equations y-2x and y-kx=7 are parallel, what is the value of k?

6. Write the equation of a line that passes through the point (-5,3) and is perpendicular

to y=35x+2.

7. Write the equation of a line that passes through the point (3,54) and is parallel

to 12x-34y=10.

8. Are the lines 4x-9y=8 and 18x+8y=7 parallel, perpendicular, or neither? Explain.

9. Are the lines 3x+2y=74 and 9x-6y=15 parallel, perpendicular, or neither? Explain.

10. Line contains points (−4,2) and (−2,9). Line contains points (,−1) and (−1,1).

a. Find the value of if the lines are parallel.

b. Find the value(s) of if the lines are perpendicular.

11. Find the distance between the point (0,0) and the line y=x+10.

Name ______Module 4

Equations of Parallel and Perpendicular Lines Exit Ticket

Write the equation of the line that contains the point (−2,7) and is

a. Parallel to x=3.

b. Perpendicular to x=-3.

c. Parallel to y=6x-13.

d. Perpendicular to y=6x-13.