What a proposal
In the figure below
the quadrilateral \(ABCD\) is inscribed in a circle. The lines \(AB\) and \(CD\) meet at \(E\).The diagonals \(AC\) and \(BD\) meet at \(F\). The circumcircles of the triangle \(AFD\) and \(BFC\) meet again at \(H\). Find the measure of angle \(EHF\) in degrees.