Need derailleur hanger
Here's a link to the to a website that discusses how to determine from the serial number what year your Cannondale was made. 
http://vintagecannondale.com/info/serial_numbers/
Then you can  cross reference that year's catalog, determine the model you have and then be able to get a list of parts/part numbers. The relevant letters and numbers should be stamped on the underside of the bottom bracket shell. Between 1993 &amp; 1999, a two letter code stamped in one corner of the underside of the BB shell represents the year and month of manufacture. The letter F happens to represent 1994. See website. 
Once you've determined the year made, a Google search (example: "1994 Cannondale catalog")  will turn up hits that link to a PDF file of that years catalog. Utilizing color scheme and component clues, you then locate the correct model.  With this knowledge you can call up the correct part and part numbers. This may sound convoluted but in just a couple minutes, I had a catalog downloaded and was ready to find a match. Bear in mind that the bike may be manufactured in the year prior to it's model year (the first 2019 bikes were being produced as early as last summer). So one may have to look at, 4say, a 1995 catalog for the correct bike despite sporting a "born on" date of 1994.
Here's another helpful link on the subject:
https://derailleurhangerstore.co.uk/pages/how-to-identify-your-derailleur-hanger
Good luck!