The Faithfull Plastic Quick Square, also known as a layout or angle square, is a tool designed for carpenters to quickly and accurately mark out for building projects, particularly when constructing roof rafters.Manufactured from engineering plastic and has imperial graduations marked with degree measurements to make material layout and timber cutting easier.It can be used as a protractor, try square, mitre square, framing square, or for measuring quick and easy 90 and 45 degree angles. The square is durable, flexible, and the ideal tool to calculating hips, valleys and angles on roofs.