Subtract the tower volume from the roof

- [Instructor] Next we need to cut this roof slope back,…because the tower walls are going to rise up through it.…Examine this sketch over here, and it shows the situation…where the roof wraps around the tower walls.…Let's trace over the tower walls.…Reset the UCS to world first by typing…UCS enter enter, and then draw a rectangle,…tracing the exterior of the tower walls.…And then move the last object, L, over this way 200 feet.…

That was the initial offset that we made when we…set up the project.…And you can see the relationship now…between tower walls and the second floor plan.…They're lined up right here on the corner.…So armed with that knowledge, I'm going to move…this object over from its end point,…and I'm going to snap that right…onto the 3D model right here.…And we just need to make sure that's in the right location,…it looks like it's slightly off.…So I'm going to move that over…and do that again,…from the end point to this end point here.…

Now I'm going to extrude this rectangle down…through the roof, and then simply subtract it…