Sam's Home  Chameleon Home  Chameleon Graphing Java Applet  Ask Dr. Math 

Finding Points in the Plane We can find every point in the plane using two numbers. These numbers are called coordinates. We write a point's coordinates inside parentheses, separated by a comma, like this: (5, 6). Sometimes coordinates written this way are called an ordered pair. The first number in an ordered pair is called the xcoordinate. The xcoordinate tells us how far the point is along the xaxis. The second number is called the ycoordinate. The ycoordinate tells us how far the point is along the yaxis. Let's try an example. A fly is sitting in the plane. Sam knows that the fly is at point (4, 3). What should he do? Sam starts at the origin. So far, he has not moved along the xaxis or the yaxis, so he is at point (0, 0). Because he wants to find (4, 3), Sam moves four units along the xaxis. Next, Sam turns around and shoots his tongue three units. Sam's tongue goes straight up, in the same direction that the yaxis travels. Sam has found point (4, 3). He eats the fly happily. 
Please send questions, comments, and suggestions
to Ursula Whitcher
[Privacy Policy] [Terms of Use]
Home  The Math Library  Quick Reference  Search  Help