The thick edge is useful as a saw guide. It can be used directly with the saw against the square for cross cuts or angled cuts using the etched protractor scale. It can be used indirectly as well, using the scribing notches to create a saw cut line for rip cuts. Designed to make easy rafter pitch or slope calculations, this handy angle square is also suitable for use as a protractor, combination square and depth adjustment on table saws. The square tool is marked with inches and degrees with cast markings that won’t rub off. Easy to read and easy to use.