.
Same as the measure of the corresponding angle in the similar triangle.
In other words, angle F is congruent to the Angle E.
Explanation. In Math, when somebody says
triangle A B E is congruent to triangle D C F
it means that the vertices (and the angles) are listed in the correct/corresponding order.
Notice. It also means that the person who states the congruency, is responsible for the correctness of his words.