16.04 - Resize partition - Ask Ubuntu

recently reinstalled ubuntu server (16.04), having trouble resizing partition(s).

during installation, specified partition should 200gb (of 500gb). did because have identical computer smaller drive (250gb disk). if went wrong computer, simple restore on other computer , have , running again in no-time.

now, sure specified 200gb disk size. if @ df -h says 200gb.

(note: says 180gb arguments sake keep simple).

so, once had server installed , configured, wanted extend partition include remaining 300gb of disk space. however, when @ gparted screen

it doesn't have unallocated disk space available. do, however, have unused space.

perhaps understanding of partitioning in ubuntu incorrect. understanding that, if specify 200gb disk space, have 300gb of unallocated space. or @ least space can still allocate something. cannot resize in gparted seen in screenshot.

what did wrong , possible resize root folder max disk space?

edit: per request, output of sudo lvdisplay

--- logical volume ---
lv path /dev/enel-vg/root
lv name root
vg name enel-vg
lv uuid pzjcaf-qzg2-m9xv-lsi1-zzoj-go1e-vmikoq
lv write access read/write
lv creation host, time enel, 2016-10-18 21:32:27 +0200
lv status available
"#" open 1
lv size 182.35 gib
current le 46682
segments 1
allocation inherit
read ahead sectors auto
- set 256
block device 252:0

--- logical volume ---
lv path /dev/enel-vg/swap_1
lv name swap_1
vg name enel-vg
lv uuid ds6gta-l5uc-erpk-jx58-olgn-tvdm-teojoc
lv write access read/write
lv creation host, time enel, 2016-10-18 21:32:28 +0200
lv status available
# open 2
lv size 3.91 gib
current le 1001
segments 1
allocation inherit
read ahead sectors auto
- set 256
block device 252:1