In square \(ABCD\), points \(E\) and \(F\) lie on \(AB\) such that \(AE=EF=FB=10\). Similarly, points \(G\) and \(H\) lie on \(BC\) such that \(BG=GH=HC=10\). Let \(J\) be the intersection of line segments \(DH\) and \(CF\). The areas of \(\triangle DFJ\) and \(\triangle CJH\) are then shaded.
Determine the fraction of the area of square \(ABCD\) that is shaded.