Decades ago my loft space was a bit larger and more rectangle. I was using the bands Altec A7's, a similar two way bass reflex / horn.
An acquaintance recording Engineer had just sold me his Octavium subwoofer. After showing me how to position a subwoofer in any room he positioned speakers. Approximately 12' apart, 5' from the front wall and possibly 8" from the side walls and very little toe in. With the listening position about 10-15' with a great deal of room behind. He taped the floor with their locations. I never did exact measurements, sorry.
This was my first experience with stereo and despite scratchy LP's and FM, in hindsight this was by far my favorite in home presentation. Having all that room to myself was the bomb.
Unlike the subwoofer, he could only generally explain what to listen for when locating speakers. He warned that room uniqueness and the vast differences of speakers would be accomplished by a novice with patient experimentation and using a mirror to determine the sidewall first reflection.
Despite all the rooms and speakers in my experience I'm certain I suck at speaker positioning. I'd guess you have exactly the right type of speaker for that size room. Good luck with your setup.