How to install Qt on Ubuntu

Download Qt from here.
Assume it was downloaded to Download folder.
First, go to Download folder.
cd ~/Downloads/
Change the permission of installer.
chmod +x qt-opensource-linux-x64-1.6.0-6-online.run
Then run installer
./qt-opensource-linux-x64-1.6.0-6-online.run

If successfully, it should be like this following image.