Can't acess internet through the terminal

[sirackerman]

Why can't i access internet through the terminal ?
I can access outside website normally when i use browsers but in the terminal i always get error because of internet connections.
For example when I'm connected and I run Ping google.com I get this :

or when I try to clone repository from github i always get this kind of error:

is there any way to configure the proxy so that the terminal can have access to the proxy network?
Thanks for helps.