To angle oneself (does not necessarily have to be a forty-five degree angle) into an uncrowded area outside or inside a train or bus to gain an advantage in finding a good place to sit or stand.
Looks like I'm going to have to forty-five it before that bratty kid gets missile lock on my seat!
Phrase for claiming one's portion of a sack of marijuana, or hits from the joints rolled from it, typically one quarter of a twenty dollar portion. Also means to have a stake in, or some control of, a situation.
Nigga, I got five on tha twenty sack - Snoop Dogg, 'What's My Name?'