as requested on Facebook:
I’m trying to make a square 29.75 tall and 33.50 wide but at the top of the square I want a .75 camber across the top?
Draw the rectangle:
Set the grid to 0.75"
Move the midpoint of the top so that it is on a grid intersection:
Go into Node Edit mode:
right-click and choose “Insert Node”
Drag it up to the correct position:
If need be, select, toggle smooth, and adjust the off-curve nodes:
