Do you know how the furniture will be placed in the room, considering door openings, and windows, maybe fireplace, TV, etc? If so, you can then measure the length on the long side, if it doesn't conflict with anything. Once you have the 'long' side figured out, you can then determine if the shorter side should be on the left, or the right, or maybe even both if space permits.

Might a sofa and loveseat work as well or maybe better, or even 2 sofas?

Sue

I think all too often people limit themselves with furniture placement by buying furniture that is too big and will only 'work' one way....and heaven forbid they ever move and then try and make existing furniture fit.

Here is a link that might be useful: Google images sectional sofas

I also think a sectional in this space is too restrictive especially if you were to move down the road. I think two sofas or sofa, love combination would be better arrangement.