Plotting Points and Finding Distances

Pre-Algebra · Axiom Academy

LESSON Plotting Points and Finding Distances Plot any ordered pair by stepping across and up — then read the distance between two aligned points straight off the grid. The coordinate plane is built from two perpendicular number lines that cross at zero. The horizontal line is the x-axis , the vertical line is the y-axis , and the point where they meet is the origin . x-axis — the horizontal number line y-axis — the vertical number line Origin — the point (0, 0) where the axes meet The two axes split the plane into four regions called quadrants , numbered I, II, III, and IV counter-clockwise starting from the top right. Watch a point travel through each region — the sign of its coordinates (x, y) tells you exactly which quadrant it lands in. x negative, y positive: (-, +) x positive, y negative: (+, -) Every point is named by an ordered pair (x, y) : the first number is how far across (the x-coordinate), the second is how far up or down (the y-coordinate). To plot it, start at the origin, step horizontally by x , then step vertically by y . Watch (3, 2) get plotted step by step. When two points share the same y-coordinate, they sit on the same horizontal line. The distance between them is just how many units apart they are along that row — which you can count on the grid , or compute as the absolute value of the difference of their x-coordinates.

This is the written version of the interactive lesson above. See the full Pre-Algebra course.