Hi. Fellow odd shaped room guy here. In fact, mine is freakishly odd with multiple corners and angles. I was able to get things pretty even with two subs but only after measurement and some thoughtful problem solving.
Let me start by explaining what everyone is saying here. Almost all rooms in houses and apartments are lousy for bass. If you take a measurement at your listening position almost all locations will graph like a roller coaster. This means some frequencies will have peaks (where bass is being delivered well … sometimes too well) and nulls (where little to no bass is being delivered).
Before I "splurged" on a $70 microphone I located my sub doing the "sub crawl." The green line above was the spot in my room where bass sounded the "loudest." In actuality, I was only hearing limited parts of the bass spectrum. It was loud bass, but only at like 23Hz and 53Hz. But, the spot in my room that made the red line, which by itself didn't sound that great, ended up complimenting the first location very well. Together they make very nice bass across the entire spectrum. So, there's no magic to two subs - unless you locate them in places that allow them to make up for the other location's shortcomings.
We spend many thousands of dollars on this hobby trying to make something that sounds good and provides enjoyment. Add up the cost of a receiver, main speakers, surround speakers, subwoofers, etc. and it's got to be at least several thousand. What if there was a magic thing that could take what you have and make it sound MUCH, MUCH better? And what if that thing only costed $70?
When you ask "how many subs do I need" or "where should I put them?" you, me, and all the helpful folks here are just guessing. They may be educated guesses, but none of us know. Especially with odd shaped rooms! But for $70 you can know EXACTLY what you have, what locations are best, and what secondary locations fill in whatever gaps those primary locations might have.