Walls and Ceilings - Drywalling basement ceiling

I'm hanging drywall on my ceiling in my basement. I have a problem with an "unsquare" corner. What is the best way to handle this? This is the first time I've hung drywall so I not quite sure how to proceed.

If I square the sheet against one of the walls, it will gradually gap away from the wall. The wall will be a hallway wall with a doorway so it is only about five feet wide so the gape wouldn't be huge, probably about 3/4 of an inch. Could that be covered with molding or should it be filled in. If so, how to fill it in.

I'm new to most of this stuff so forgive my nievity.

Cut the drywall so it is exactly as "unsquare" as your corner.

I agree. It doesn't have to be 'perfect' - 1/4" off in drywall is plenty close enough, as long there are no gaps larger than 1/2" you shouldn't have any problems. A 1/2" gap should be prefilled with joint compound - let dry before taping.

Taking the time to cut the first board square will allow the others to be put in so the edges have a joist to be screwed into. Otherwise you will need to cut each board to make it fit, and have a lot of butt joints that need to be taped instead of "factory" edges.

(factory edges are the thinner ones that run along the 8 foot length)