Answer:
Step-by-step explanation:
Triangle ABC is an equilateral triangle, then:
=> angle ABC = angle BAC = angle ACB = 60 deg
AB // CE, according to alternative interior pair of angles theorem:
=> angle ACE = angle BAC = angle ABC = 60 deg (1)
B, C, and D are colinear, then:
angle ECD + angle ACE + angle ACB = 180 deg
=> angle ECD = 180 - angle ACE - angle ACB = 180 - 60 - 60 = 60 deg (2)
From (1) and (2):
=>angle ACE = angle ECD = 60 deg
