Video narration
You know how two numbers locate a point on a flat plane, but where does height fit-and which distance formula should you use? Think of locating a room by moving across, forward, and up: its position is (x, y, z). For two points, subtract matching coordinates: x2−x1, y2−y1, and z2−z1. Square each difference, add them, then take the square root. That's the Euclidean distance. From the origin, (0,0,0), use √(x2+y2+z2). Remember: three coordinates locate; match, subtract, square, add, root.