Jimmy,
The equilateral triangle is most useful for mixing or mastering. If you want a more 'realistic' presentation then I prefer speakers facing forward (not toed in) and about 2 feet apart for 3 foot listening, 4 feet apart for 6 foot back listening, and 8 feet apart for 12 foot back listening. The further back the more natural and less like headphones it will sound - however you need correspondingly bigger space as you need at least 6 feet open space behind the listener and if you place speakers 8 feet apart then you need a room that is at least 16 feet wide.
Whatever you do DO NOT sit with your head or couch up against a wall - this is the single worst thing you can do in any listening room - if you cannot hear the damage done to audio from sitting at a wall then you probably need not waste money on audio gear. I see that you have a seat closer to the middle of he room than your couch - I assume you hear the degradation from sitting at the couch and use this seat for critical listening?