We have been given a diagram. We are asked to find the segment congruent to EC.
We can see from our given diagram that segment EC is made up with segment CD and DE.
[tex]EC=CD+DE[/tex]
We can also see that segment CB is equal to segment.
[tex]CB=CD[/tex]
Further, segment BA is equal to segment DF.
[tex]BA=DF[/tex]
So sum of segment CB and BA will be equal to segment EC.
[tex]AC=CB+BA[/tex]
Therefore, segment AC is equal to segment EC.