Answer: Angle F
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Explanation:
We see that angle A = angle E as shown by the arc marking. The tickmark says that side AB is the same length as side EF.
In the letter sequences "AB" and "EF", erase the first letters A and E to be left with B and F. This is one way to show how angle B pairs with angle F, and that is enough to show the two angles are congruent.
