How far apart are these points?
In this lesson you will learn to use
absolute value to find distances
between points with the same x and y
value by using a coordinate plane.
Let’s Review
The Coordinate Plane
(5,3)
x value
(-2,-3)
y value
Let’s Review
Absolute Value:
The distance a number is from zero on the number
line.
|3| = 3
|-3| = 3
A Common Mistake
Begin by moving along the y-axis first, and then along the x-axis
when finding an ordered pair.
(6,4)
A Common Mistake
Returning to the origin after plotting the x value, and
then moving on the y-axis.
(6,4)
Core Lesson
A (6,4)
B (6,0)
A
4 units
B
|4 – 0| = |4| = 4
OR
|0 – 4| = |-4| = 4
Core Lesson
C (5,-6)
D (0,-6)
5 units
C
D
|5 – 0| = |5| = 5 OR
|0 – 5| = |-5| = 5
Core Lesson
E (0,4)
6 units
F (6,4)
E
F
|0-6|= |-6| = 6
OR
|6 – 0| = |6| = 6
In this lesson you have learned to use
absolute value to find distances
between points with the same x and y
value by using a coordinate plane.
Guided Practice
What is the distance between the two coordinate pairs A (2,-3) and B (0,-3)?
Use absolute value and the coordinate plane to solve the problem.
Guided Practice
What is the distance between the two coordinate pairs
C (-5,0) and D (-5,-9)?
Use absolute value and the coordinate plane to solve the problem.
Extension Activities
Dice Challenge:
1. Roll two dice and use the numbers as the x and y
values in an ordered pair. Plot the point on a coordinate
plane.
2. Create a point on the x or y-axis that creates a line
with your original point.
3. Find the distance between the two points.
Extension Activities
Human Coordinate Plane:
Create a large coordinate plane on the classroom floor using
masking tape.
Have one person stand at a point on either the x or y-axis.
Have another person stand on the coordinate plane at a point that
shares either the x or y value as the first person.
Have the class find the distance between the two points.
Quick Quiz
Which of the following coordinate pairs has a distance
that is 8 units long?
a. (0,-4)
(-4, -4)
b. (-3,6)
(-3, 0)
c. (0,-5)
(8, -5)
Quick Quiz
Which of the following coordinate pairs has an
absolute value of -4?
a. (0,-4)
(-4, -4)
b. (-3,6)
(-3, 0)
c. (0,-5)
(8, -5)