Square \(ABCD\) has area \(200\). Point \(E\) lies on side \(\overline{BC}\). Points \(F\) and \(G\) are the midpoints of \(\overline{AE}\) and \(\overline{DE}\), respectively. Given that quadrilateral \(BEGF\) has area \(34\), what is the area of triangle \(GCD\)?