I was trying to find an equation to find the area of any regular polygon and I came up with this:

$\displaystyle A=\frac{tan(90-\frac{180}{s})d^2s}{4} $

$\displaystyle s$=# of sides

$\displaystyle d$=length of each side

and $\displaystyle 90-\frac{180}{s} $ comes out in degrees

I think this equation works but I'm not sure, does it? Also, is there an easier equation out there?