E is the mid-point of line AC.
`thereforeCE=1/2AC" "...(1)`
In `DeltaABE,`
Since, D is the mid-point of CB and `DF"||"BE`
`therefore"F will be the mid-point of CE."" "("coverse of mid-point theorem")`
`implies" "CF=1/2CE`
`implies" "CF=1/2xx1/2AC" "["from"(1)]`
`implies" "CF=1/4AC`