I really don't get how to do this

I can only figure out the easy straight lines, but when it's a shape I can't really understand it.

Can somebody give me a REALLY good guide to help me with the graphing and all that.

I need help with this probelm as well...

State the Domain and state the range.

(here are all the corners on the graph)

(-1,0),(-4,4),(5,0),(2,4)