Coordinate geometry

By Vivek Thilak

*Coordinate Geometry

Copyright © 2000 by Monica Yuskaitis

*Definition

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


*Definition* Coordinate grid – a grid used to locate a point by its distances from 2 intersecting straight lines.

ABCDE

1 2 3 4 5

What are the coordinates

for the house?


*Definition* x axis – a horizontal number line on a coordinate grid.

1 2 3 4 50 6 x


*Hint* x is the shortest and likes to lie down horizontally.

1 2 3 4 50 6 x


*Definition* Coordinates – an ordered pair of numbers that give the location of a point on a grid. (3, 4)

12345

0

6

1 2 3 4 50 6

(3,4)


*Definition* y axis – a vertical number line on a coordinate grid.

12345

0

6

y


*Hint* y is the tallest and stands upright or vertically.

12345

0

6

y


*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.

1

32

45

0

6

1 2 3 4 50 6

(3,4)


*How to Plot Ordered Pairs* Step 1 – Always find the x value first, moving horizontally either right (positive) or left (negative).

1

32

45

0

6

1 2 3 4 50 6

(2, 3)

y

x


*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).

1

32

45

0

6

1 2 3 4 50 6

(2, 3)(2,3)y

x


*How to Find Ordered Pairs* Step 1 – Find how far over horizontally the point is by counting to the right (positive) or the left (negative).

1

32

45

0

6

1 2 3 4 50 6

(5, )

y

x


*How to Find Ordered Pairs* Step 2 – Now count how far vertically the point is by counting up (positive) or down (negative).

1

32

45

0

6

1 2 3 4 50 6

(5,4)

y

x


*What is the ordered pair?

1

32

45

0

6

1 2 3 4 50 6

(3,5)

y

x

*ENDBY DEVIKA THILAK


Technology

Coordinate geometry