Final answer:
The equation EFI/CD = 2/EF = 1/AB + 1/CD represents the relationship between the length of segment EFI and the sum of segments AB and CD.
Step-by-step explanation:
The equation EFI/CD = 2/EF = 1/AB + 1/CD represents the relationship between the length of segment EFI and the sum of segments AB and CD. This can be seen by rearranging the equation to isolate EFI: EFI = (2CD)(EF)/(CD + EF). So, the length of EFI is directly proportional to the sum of AB and CD.