4/20: Digital Learning Day

4/20: Digital Learning Day

Complete this lesson for a GRADE for you digital learning day.

Today's focus: parallel and perpendicular lines

• This will be a review/practice of everything we have covered so far about parallel and perpendicular lines.

• Complete all slides for full participation credit.

Let's start with a review of slope. We know 4 ways to find slope.

• Using a graph.

• Using an equation in slope-intercept form.

• Converting an equation from standard form to slope-intercept form.

• Using two points on a line.

Multiple Choice

What is the slope of the graph shown?

• 3/2

• -3/2

• -2/3

• 2/3

Multiple Choice

The equation of a line is $y=-8x+37$ 

What is the slope of this line?

• 8

• -8

• 37

• -37

Multiple Choice

Convert the equation below to slope-intercept form.

 $6x+2y=24$  

•  $y=3x+12$  

•  $y=-3x+12$  

•  $y=\frac{1}{3}x+4$  

•  $y=-\frac{1}{3}x-4$  

Multiple Choice

The equation of Line A is $2x+3y=12.$  

The equation of Line B is  $4y-6x=20$  .

Are these lines parallel, perpendicular, or neither?

• Parallel

• Perpendicular

• Neither

Multiple Choice

What is the slope of the equation below?

 $6x+2y=24$  

• -1/3

• 1/3

• 3

• -3

Multiple Choice

What is the slope of a line containing the points (5,6) and (21,-2)?

• -1/2

• 1/2

• 2

• -2

Multiple Choice

Line A contains the points (2,4) and (5,8).

Line B contains the points (3,5) and (6,9).

Are these lines parallel, perpendicular, or neither?

• Parallel

• Perpendicular

• Neither

What do we know about parallel lines?

The slopes of parallel lines are identical!

They are equal!

They are the same!

Fill in the Blank

The line shown has an equation of y=2x+4. If you made another line that what parallel to this one, what would its slope be?

Fill in the Blank

The line shown has an equation of $y=-\frac{2}{3}x+5$ . If you made another line that what parallel to this one, what would its slope be?

Multiple Choice

Which line would be parallel to the line $y=\frac{4}{7}x+9$  ?

•  $y=\frac{7}{4}x+3$  

•  $y=-\frac{7}{4}x+10$  

•  $y=\frac{4}{7}x-4$  

•  $y=-\frac{4}{7}x-12$  

Multiple Choice

Which of the following equations represent a pair of parallel lines?

 $a.\ \ y=-5x+2$  

 $b.\ \ 5y=-25x+75$  

 $c.\ \ y=\frac{1}{5}x+14$   

 $d.\ \ y=-\frac{1}{5}x+9$  

• A and B

• A and C

• A and D

• B and C

Multiple Choice

Write the equation of a line that is parallel to $y=\frac{1}{5}x-3$   and goes through the point (1,1).

•  $y=\frac{1}{5}x+0.2$  

•   $y=\frac{1}{5}x+0.8$  

•  $y=-5x+0.8$  

•  $y=5x+0.2$  

What do we know about perpendicular lines?

• The slopes of perpendicular lines are opposite reciprocals.

• This means that they have OPPOSITE signs (one positive, one negative).

• They ALSO must be flipped fractions (reciprocals).

Multiple Choice

Which two fractions are OPPOSITE RECIPROCALS?

• $\frac{1}{4}\ \ and\ \ \frac{3}{12}$

• $\frac{1}{4}\ and\ \frac{4}{1}$

• $\frac{1}{4}\ and\ -\frac{4}{1}$

• $\frac{1}{4}\ and\ \frac{2}{4}$

Multiple Choice

The graph shown has an equation of $y=3x-5$ . If you made another line perpendicular to the one shown, what would its slope be?

• 3

• -3

• 1/3

• -1/3

Multiple Choice

The graph shown has an equation of $y=-\frac{4}{5}x+4.$ If you made another line perpendicular to the one shown, what would its slope be?

• -5/4

• 5/4

• -4/5

• 4/5

Multiple Choice

Which line would be perpendicular to the line $y=-8x-5$  ?

•  $y=\frac{1}{8}x+82$  

•  $y=-\frac{1}{8}x-5$  

•  $y=-8x+5$  

•  $y=8x+10$  

Multiple Choice

Which of the following equations represent a pair of perpendicular lines?

 $a.\ \ y=-\frac{3}{18}x+9$  
 $b.\ \ y=\frac{1}{6}x+12$  
 $c.\ \ y=6x-7$  
 $d.\ \ y=-\frac{5}{10}x+4$  

• A and B

• A and C

• C and D

• B and D

Multiple Choice

Write the equation of a line that is perpendicular to $y=\frac{4}{9}x-3$  and goes through the point (-2,5). 

•  $y=\frac{4}{9}x+0.5$  

•  $y=\frac{9}{4}x-3$  

•  $y=-\frac{9}{4}x+0.5$  

•  $y=-\frac{9}{4}x-2$  

Poll

How comfortable do you feel, overall, with parallel and perpendicular lines?

• Very comfortable. I could teach someone else about them.

• Pretty comfortable. I think I would do well on a test/quiz about them.

• I'm not sure. I need some more review and help.

• Not comfortable at all. I need a lot more help before I would be ready for a test/quiz.