Linux – create a new partition command line

My situation: there was RAID setup between 3 physical hard disks, however one of them was considerable bigger – about a couple of TBytes.
I needed the additional space for other purposes so I needed to create a new partition and ideally avoid rebooting the server.

The plan is to create an extended partition that will contain a logical Linux partition mounter to a new folder

Identify where to create the new partition, in my case sdc:
fskdisk -l

creating an extended partition

to avoid reboot one may try

creating a linux type partition from the extended one we creted