Question 529787
A square, by definition, has equal side length for all 4 sides. So let's use the distance formula between any two adjacent points.

Try, (0,0) (0,m)

sqrt((0-m)^2 + (0,0))
sqrt(m^2)
m

Our side length is m.

Let's assume m is a positive number.

Then (0,0) is our bottom left corner.
(m,0) is our bottom right corner
(0,m) is our top left corner

We need to find the top right corner.

We need to travel m units up from our bottom right corner.
or
We need to travel m units right from our top left corner.

Either way we will end up with the same point (m,m) which is our 4th vertex. So our square is (0,0) (m,0) (0,m) (m,m)