A few days ago I was asked how to calculate the size of setting triangles for an on-point setting. I thought a post focused on that would help others, too.
[For information to help decide whether to set your center block on point, see this post.]
Have you ever made a block-format quilt with a diagonal setting? The math for setting triangles is the same as that for the setting corners on that block quilt.
How large will your new block be?
finished center x 1.414 = finished size of on-point block
ex: 20″ x 1.414 = 28.28″.