\[\angle AEF = 58{^\circ};\ \ \angle CED = 49{^\circ};\ \ \]
\[\angle AED = 90{^\circ}\ (прямой\ угол).\]
\[\angle AEF + \angle CED = 58{^\circ} + 49{^\circ} =\]
\[= 107{^\circ}\]
\[\angle CEF = 107{^\circ} - \angle AED =\]
\[= 107{^\circ} - 90{^\circ} = 17{^\circ}\]
\[Ответ:\angle CEF = 17{^\circ}.\]