Finding the area of a quadrilateral I have a quadrilateral whose four sides are given 

$2341276$, $34374833$, $18278172$, $17267343$ units.

How can I find out its area? What would be the area?
Have you seen this (MathWorld article)? In particular, the area of a planar convex quadrilateral is given by $\frac{1}{4}(b^2+d^2-a^2-c^2) \tan \theta$ where $a,b,c$ and $d$ are the side lengths.
If  unlike sidelengths actually restrict formation any other quad then our given quad becomes unique and even geometrically we cannot change theta values i.e angles for the given quad.