Name ____________________________ Date _____________ Period _______
Parallel or Perpendicular or ??
Parallel Lines
Definition:
Perpendicular Lines
Definition:
Decide whether the pictures shown represent parallel lines, perpendicular lines or neither
one. Briefly describe how you made your decision.
circle one:
How do you know? Describe your method:
Parallel
Perpendicular
Neither
circle one:
How do you know? Describe your method:
Parallel
Perpendicular
Neither
circle one:
How do you know? Describe your method:
Parallel
Perpendicular
Neither
circle one:
Parallel
Perpendicular
Neither
How do you know? Describe your method:
Parallel or Perpendicular or ??
Use the given equations to find the y values and complete both In/Out tables. Plot both sets
of points on the axes below draw the two lines represented.
y = 3x + 3
x
-3
-2
0
-1
2
1
y = 3x - 1
y
x
y
2
-1
0
-2
1
3
What do you notice about these two lines and the slope of these lines?
Use the given equations to find the y values and complete both x/y tables. Plot both sets of
points on the axis below draw the two lines represented.
y =

2
x-2
3
x
y = -
y
x

3
2
6
4
0
0
-3
-2
-6
-4
9
6
3
x+1
2
y
What do you notice about these two lines and the slope of these lines?
Use the given equations to find the y values and complete both x/y tables. Plot both sets of
points on the axis below draw the two lines represented.
y = 4x - 8
x
y =
y
x

2
2
3
4
0
0
1
-2
1
2
-4
1
x+1
2
y
6
4

What do you notice about these two lines and the slope of these lines?
For each pair below, guess whether they will be parallel, perpendicular or neither by circling.
Then graph them to prove whether your guess was right or wrong. Conclude by stating
whether you were correct and describe how you knew, or how you were incorrect and why.
1. 𝑦 = 𝑥 + 1
Guess by
circling one:
𝑎𝑛𝑑
𝑦 =𝑥−5
Conclusion:
Prove by Graphing:
Parallel
Perpendicular
Neither
2. 𝑦 = 3𝑥 − 1
Guess by
circling one:
𝑎𝑛𝑑
1
𝑦 =− 𝑥+4
3
Prove by Graphing:
Conclusion:
Parallel
Perpendicular
Neither
3. 𝑦 = 2𝑥 − 1
Guess by
circling one:
Parallel
Perpendicular
Neither
𝑎𝑛𝑑
𝑦 = −2𝑥 + 4
Prove by Graphing:
Conclusion:
Write a summary below. Describe how you can tell whether or not an
equation will be parallel, perpendicular or neither. Use examples of
equations, graphs or tables to help explain.