D. E are the points on the sides BC and AC of equilateral △ ABC, and BD = CE, connect be = ad, they intersect at point F, find the degree of angle AFE

D. E are the points on the sides BC and AC of equilateral △ ABC, and BD = CE, connect be = ad, they intersect at point F, find the degree of angle AFE

The congruence method of ACD and Bae is the same as that of abd and BCE, so there is angle CAD = angle Abe. In triangle Abe, the sum of inner angles is 180 degrees, that is, angle Abe + angle AEB = 180 degrees - angle EAB (60 degrees) = 120 degrees, then angle CAD + angle AEB = 180 degrees - angle EAB (60 degrees) = 120 degrees in triangle AEF