Coordinate Geometry

A map is a drawing that shows a place from above, like a park or a treasure island.
It helps us see where things are, like trees, paths, or a treasure chest.

On a map, a grid helps us find where things are.
Each square on the grid has a name made of a letter and a number.

• The letter tells us the column. We read the letters along the horizontal axis (from left to right).
• The number tells us the row. We read the numbers along the vertical axis (from bottom to top).

The treasure is in square C2. We say C2 because the treasure is in column C and row 2.

A coordinate plane is a grid formed by two number lines that cross at zero. One number line goes left and right (called the x-axis), and the other goes up and down (called the y-axis). The point where they cross is called the origin and has coordinates \((0,0)\).
The coordinates of a point are a pair of numbers, like \(A(3,2)\). The first number is the \(x\)-coordinate and tells you how far to move along the \(x\)-axis. The second number is the \(y\)-coordinate and tells you how far to move along the \(y\)-axis.

Plot these points on a coordinate plane: \(A(2,3)\), \(B(4,2)\), and \(C(0,1)\).