18) EAF =

\(\angle EAF = \angle ZAF - \angle ZAE\)

\(\angle ZAE\) = 180° - \(\angle ZAB\) - \(\angle BAE\) = 180° - 20° = 160°

\(\angle ZAF\) = 180° - \(\angle ZAB\) - \(\angle BAF\) = 180° - 40° = 140°

\(\angle EAF\) = 140° - 160° = 20°

Ответ: 20°