At the first time I was using PrtSc (Print Screen) button to take a screenshot on Ubuntu, but it was not satisfying because it took the entire screen. I want resizeable screenshot with chosen area.
I found How to take a screenshot on Ubuntu Linux which talked about it. I found it was using the imagemagick. You can install it by running this command.
sudo apt-get install imagemagick
How to use is very easy, just simply running this command, from your terminal.
The screen will be frozen waiting for you to drag/select area you want to take.
Using Gnome screenshot command
Instead of installing imagemagick, you can also take a screenshot by default screenshot program. Run this command on your terminal.
The option -a stands for AREA which means you are able to select the area you want to take. If you want to read further explanation you can visit How to Take a Screenshot in Linux (GNOME) or type.
To see available options which will helps you out.