I have two 45° triangles that are very accurate but, I don't like to use them for everyday work...
So I "Copy" and "Paste" them to plywood
I used 1/4" (6mm) plywood but you can use any.
Just to save you the calculations:
440mm = 17-5/16"
640mm = 25-3/16"
Another simple, yet effective idea, Niki. Thanks for posting it.
When the going gets weird, the weird turn pro. - Hunter S. Thompson
When the weird get going, they start their own forum. - Vaughn McMillan