The labelled diagram of the given figure is shown below
Two triangles are similar if the ratio of their corresponding sides is equal.
If triangle ACE is similar to triangle ECD, then it means that
AC/EC = BC/DC = AB/DE = 4
We know that
angle ACB is congruent to anle ECD and the angle is 90 degrees
Thus, the similarity postulate that must be used is
Side Angle Side(SAS)
