If you're resizing a partition, you just unmount it and use the partition manager and specify the size.

If it happens to be your root partition, you need to boot off of usb stick or something as the partition should not be mounted.

1. boot off a usb disk like the net install image on a usb stick.
2. drop to the friendly command line
3. "modprobe dm-crypt" to load the encryption module
4. "cryptsetup luksOpen /dev/sda1 crypt1" to unencrypt the partition where /dev/sda1 is your encrypted luks partition
5. "lvm vgscan --mknodes" and "lvm vgchange -ay" to activate the encrypted partition
6. "e2fsck -f /dev/mapper/vg_tedst410-lv_root" to check the partition
   
7. "resize2fs -p /dev/mapper/vg_tedst410-lv_root 200g" to resize that file-system to 200 gigs (yes that's the file system only, not the partition)
8. "e2fsck -f /dev/mapper/vg_tedst410-lv_root" to check to make sure it's still ok
9. "lvreduce -L 200G /dev/vg_tedst410/lv_root" to resize the partition to 200 gigs.

I wrote this after I ran all the commands so double check the parameters before running it.