I figured out how to use 3 variables to represent a rectangle in a grid instead of using 4.
The traditional way is to use (x,y) (x2,y2). I propose using (x,l,h).
In the traditional way as you probably know, (x,y) is the left op most corner, and (x2,y2) is the bottom right most corner. In the way I am proposing X is the left side, l is the length of the top side, and also the length of the bottom. 'h' is the height of the left and right. I think it's obvious how these three can define a rectangle same as the four.
It isn't much saved space considering todays computers, but it is something.
On a grid, the x is not enough information. You might know how far the rectangle is offset from the y-axis, but you do not know how far the rectangle is offset from the x-axis, or its y-coordinate.
You still need (x, y) to represent one corner of the rectangle, and (l,h) to represent the size of the sides, which is the same as using (x, y) and (x_1, y_2)