Yes they are with in a few inch of 45 degree I got lucky where the floor joist where. Here is the mount I used https://www.amazon.com/gp/product/B005BV0FHG/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
I had thought about monopoles for the sides and rear, but Iam only 3ft or so from the sides...