Step-by-step explanation:
Given
[tex]CF=EG\\CD=EF[/tex]
Now, CF and EG can be breakdown to written as
[tex]\Rightarrow CD+DF=EF+FG[/tex]
Now CD can be replaced by EF as they are equal
[tex]\Rightarrow EF+DF=EF+FG\\\Rightarrow DF=FG[/tex]
Hence proved
