Angle-izer Template Tool
This is the ultimate tool for the do-it-yourself types from builders to weekend warriors. Perfect for laying down tile, paver bricks, arches, bullseyes, corbelling, and more. No more crazy calculations to get the perfect angle. Just re-create the angle with the General Tools 836 Angle-izer Template Tool and be done in seconds not minutes. It is also pretty inexpensive ($14 here), built to last, and fits in just about any toolbox.