hello

i would like to be able to snap one of my lines to vertical, whats the easiest way to do this, for example if i draw a hexagon and then accidentally turn it ,how do i get one edge vertical.

I'd use snapping and guides:

You can snap horizontally also.

cool, i knew it would be easy, thank you

what about an odd shape for instance a coffin shape that the sides aren't all even

can i rotate around a corner and not the centre

Yes, the center of rotation can be snapped to a corner, then the object can be rotated until another corner snaps. It can be finicky, but it generally works.

thank you