I should ask which partition do you want to remove. A default FC1 install has 3 partitions. /, /boot and swap. If you want to delete any of these you need to boot from the 1st CD to rescue mode.
BTW fdisk is located in the /sbin directory. You need to be logged in as root to use this utility. Also /sbin is not in a regular users path so you will get a command not found error. The command for using root's environment is: