Please note: there is an APT package called "fonts-powerline" which is tested and working for Ubuntu 20.04 which achieves the same outcome. Try "sudo apt install fonts-powerline"
If you're using Z Shell and a special prompt theme designed with Powerline fonts in mind, you'll need to install them on your machine. These are the most clear and cut-down instructions that I've found to work with Ubuntu 16.10 (also confirmed working for 17.04, 17.10, 18.04, 19.10) and all credit goes to renshuki's Ubuntu 14.04 + Terminator + Oh My ZSH with Agnoster Theme gist. I've extracted just the Powerline font instructions - my personal setup uses Prezto instead of Oh My ZSH (not included here).
cd ~
wget https://github.com/powerline/powerline/raw/develop/font/PowerlineSymbols.otf
wget https://github.com/powerline/powerline/raw/develop/font/10-powerline-symbols.conf
mkdir ~/.fonts #if directory doesn't exist
mv PowerlineSymbols.otf ~/.fonts/
mkdir -p ~/.config/fontconfig/conf.d #if directory doesn't exists
fc-cache -vf ~/.fonts/
mv 10-powerline-symbols.conf ~/.config/fontconfig/conf.d/
Restart your terminal and your powerline fonts should be working.
@rafaelribeiroo I'm not aware of any workaround that could avoid the terminal restart. But please let me know if you find anything.