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Is there a formula/calculation to work out how to find the other $2$ coordinates for a rectangle if you only have the bottom left and top right coordinates?

e.g. My bottom-left coordinate would be $(-1, 0)$ and top right would be $(3, -2)$, I can work out the midpoint but I can't seem to get my head around how to work out the other $2$ coordinates?

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    @RagibZaman,I am not sure about that..draw the circle with radius half of the diagonal and mid$p$oint as center then each $p$oint on the circle can be vertice $p$oint of the rectangle2011-11-24

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Let's observe picture below. Each point $(x,y)$ of the circle that satisfy following equality can be vertice point of the rectangle :

$\left(\sqrt{(x_A-x)^2+(y_A-y)^2}\right)^2 + \left(\sqrt{(x_C-x)^2+(y_C-y)^2}\right)^2=\left(\sqrt{(x_A-x_C)^2+(y_A-y_C)^2}\right)^2$ ,

where $A(-1,0)$ , and $C(3,-2)$ are given vertices.

For example if you choose point $B_1$ you can calculate coordinates of $D_1$ by using equalities :

$x_{D_1}=2x_O-x_{B_1}$ , and $y_{D_1}=2x_O-y_{B_1}$

Answer to sub question :

If you have length of one edge , let's say $|\bar{AB_1}|$ then you can write an extra equality :

$ |\bar{AB_1}|= \sqrt{(x_A - x)^2+(y_A-y)^2}$ , and find relation between $x$ and $y$ coordinates.

enter image description here

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    Sorry to be so pre-school but if I did set a length for one of the edges how would I then find the coordinates?!2011-11-24
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In your example, the bottom left coordinate is higher up than the top right coordinate.

Suppose that $b and $a. If the bottom left coordinate is $(a,b)$ and the top right is $(c,d)$, then the top left coordinate would be $(a,d)$ and the bottom right would be $(c,b)$.

Other cases can be worked out similarly.

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    Thanks Joe, just noticed I had my numbers mixed up!!2011-11-24
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I agree with top left coordinate would be (a,d) and the bottom right would be (c,b). But, it is taking an assumption that the rectangle is not rotated. If rectangle is rotated wrt to our x,y coordinates then we need to transform our x,y axis.