x1 is the horizontal coordinate (along the x axis) of Point 1, and x2 is the horizontal coordinate of Point 2. y1 is the vertical coordinate (along the y axis) of Point 1, and y2 is the vertical coordinate of Point 2. For an example, take the points (3,2) and (7,8). If (3,2) is (x1,y1), then (7,8) is (x2,y2).
Find the distance along the y-axis. For the example points (3,2) and (7,8), in which (3,2) is Point 1 and (7,8) is Point 2: (y2 - y1) = 8 - 2 = 6. This means that there are six units of distance on the y-axis between these two points. Find the distance along the x-axis. For the same example points (3,2) and (7,8): (x2 - x1) = 7 - 3 = 4. This means that there are four units of distance separating the two points on the x-axis.
62=36{\displaystyle 6^{2}=36} 42=16{\displaystyle 4^{2}=16}
To carry on the example: the distance between (3,2) and (7,8) is sqrt (52), or approximately 7. 21 units.
