Because vf vi at you know that. Find 1-D distance by subtracting the value of the coordinates for the two points. Large dsqrt left x_ 2-x_ 1right 2left y_ 2-y_ 1right 2.
Firstly find the length of one side by measuring it.
You still need the distance and you can get it this way. 10 sqrt -2 - 42 -1 - y2 10 2 421y2. Measure the length between the ground and your eyes in meters or feet. Finally solve the equation to know the length of the diagonal of the square.