Calculating the area of an irregular polygon Given the length of the sides of an irregular polygon (no coordinates provided) how do you compute the area of the maximum area of the polygon? 

Thanks in advance
The polygon must be cyclic. For details, check this out.
because we know the sides So the angles formed by these sides at the center of the circle will be in the same ratio as the sides
for example if the sides of the polygon are a,b,c,d and e then the sum of all the angles at the center will be = a*x+b*x+c*x+d*x+e*x and this sum will be equal to 360.Sonow we know all the angles made by the sides at the centre. Now we can find the area of each triangle and sum of these areas is the area of the polygon