Coordinate Plane
The plane uses an x-axis and y-axis to locate points as ordered pairs.
About this topic
The coordinate plane is a flat grid made from a horizontal x-axis and a vertical y-axis that cross at the origin (0, 0). Every point is located by an ordered pair (x, y): move x units across, then y units up or down. The axes split the plane into four quadrants, numbered counterclockwise starting from the upper right.
René Descartes popularized the idea in the 1600s, and it joined algebra and geometry for the first time. A shape can now be described by an equation, and an equation can be seen as a picture. For example, the point (3, -2) lies three units right of the origin and two units down, in quadrant IV. The distance between two points comes from the Pythagorean theorem, and the midpoint is found by averaging the coordinates.
Maps, video games, GPS systems, spreadsheets charts and computer screens all rely on coordinates to place things exactly. Latitude and longitude are a coordinate system wrapped around a sphere.
A common mistake is reversing the order of the pair. Always go along the x-axis first, then up or down. Remember also that points on an axis belong to no quadrant, and that the scale on each axis may differ, so read the tick marks carefully.
Key ideas
- Points are written (x, y)
- Four quadrants split the plane
- The origin is (0, 0)
Quick check
Use cases: where Coordinate Plane helps
- Homework: review the key idea behind Coordinate Plane before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Coordinate Plane without notes.
- Visual learning: play with the interactive lab to see how Coordinate Plane changes when you adjust its inputs.
- Teaching a friend: explain Coordinate Plane in your own words, then compare your version with the key ideas.
Number and algebra skills are used in science, engineering, budgeting and computing.
Frequently asked questions
What is Coordinate Plane?
The plane uses an x-axis and y-axis to locate points as ordered pairs.
What will I learn in Coordinate Plane?
Points are written (x, y). Four quadrants split the plane. The origin is (0, 0).
Is Coordinate Plane part of Mathematics?
Yes. It is one of 200 Mathematics topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Coordinate Plane lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Coordinate Plane?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.