1. Coordinate Geometry

2. Example of Graph Paper

3. Definition
Grid – A pattern of horizontal and vertical lines, usually forming squares.

4. Definition
Coordinate grid – a grid used to locate a point by its distances from 2 intersecting straight lines. A
What are the
coordinates
for the house? B C D E 1 2 3 4 5

5. x Definition x axis – a horizontal number line on a coordinate grid. 11 2 3 4 5 6

6. x Hint x is the shortest and likes to lie down horizontally. 1 2 3 4 51 2 3 4 5 6

7. y Definition y axis – a vertical number line on a coordinate grid. 6 54 3 2 1

8. Hint
y is the tallest and stands upright or vertically. 6 y 5 4 3 2 1

9. Definition
Coordinates – an ordered pair of numbers that give the location of a point on a grid. (3, 4) 6 5
(3,4) 4 3 2 1 1 2 3 4 5 6

10. Hint
The first number is always the x or first letter in the alphabet. The second number is always the y the second letter in the alphabet. 6 5
(3,4) 4 3 2 1 1 2 3 4 5 6

11. How to Plot Ordered Pairs
Step 1 – Always find the x value first, moving horizontally either right (positive) or left (negative).
(2, 3) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

12. How to Plot Ordered Pairs
Step 2 – Starting from your new position find the y value by moving vertically either up (positive) or down (negative). 6
(2, 3) 5 4 y
(2,3) 3 2 1 x 1 2 3 4 5 6

13. How to Find Ordered Pairs
Step 1 – Find how far over horizontally the point is by counting to the right.
(5, ) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

14. How to Find Ordered Pairs
Step 2 – Now count how far vertically the point is by counting up.
(5,4) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

15. What is the ordered pair?
(3,5) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

16. What is the ordered pair?
(2,6) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

17. What is the ordered pair?
(4,0) 6 5 4 y 3 2 1 x 1 2 3 4 5 6
Copyright © 2000 by Monica Yuskaitis

18. What is the ordered pair?
(0,5) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

19. What is the ordered pair?
(1,1) 6 5 4 y 3 2 1 x 1 2 3 4 5 6

20. What is the ordered pair?6 5 4 y 3 2 1 x 1 2 3 4 5 6

21. Let’s Try X Y 3 4 5 6 7 8 X Y 1 6 2 7 3 9 X Y 1 6 2 7 3 8

22. Print the next slide for practice
Copyright © 2000 by Monica Yuskaitis

23. What is the ordered pair?6 5 4 y 3 2 1 x 1 2 3 4 5 6
Copyright © 2000 by Monica Yuskaitis

24. Four Quadrants of Coordinate Grid
When the number lines are extended into the negative number lines you add 3 more quadrants to the coordinate grid. y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

25. Four Quadrants of Coordinate Grid
If the x is negative you move to the left of the 0.
x = -2 y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

26. Four Quadrants of Coordinate Grid
If the y is negative you move down below the zero.
y = -3 y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

27. How to Plot in 4 Quadrants
Step 1 - Plot the x number first moving to the left when the number is negative.
(-3, -2) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

28. How to Plot in 4 Quadrants
Step 2 - Plot the y number moving from your new position down 2 when the number is negative. y 3 2
(-3, -2) 1 x -1 -2 -3 -3 -2 -1 1 2 3

29. How to Plot in 4 Quadrants
When x is positive and y is negative, plot the ordered pair in this manner. y 3 2
(2, -2) 1 x -1 -2 -3 -3 -2 -1 1 2 3

30. How to Plot in 4 Quadrants
When x is negative and y is positive, plot the ordered pair in this manner. y 3 2
(-2, 2) 1 x -1 -2 -3 -3 -2 -1 1 2 3

31. Plot This Ordered Pair
(-3, -3) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

32. Plot This Ordered Pair
(-1, 2) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

33. Plot This Ordered Pair
(1, -1) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

34. Plot This Ordered Pair
(2, -2) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3

35. Plot This Ordered Pair
(-3, -2) y 3 2 1 x -1 -2 -3 -3 -2 -1 1 2 3