ALVIN - 10 inches Smoke-Tint Acrylic Triangle Ruler 30/60 Degrees, Multipurpose Tool for Drafting, Design, and Architecture, Great for Machining and Woodworking

Plastic drafting triangles are super useful for all manner of layout work on carpentry and woodworking projects. This set is a good example of the ones I use which are certainly a different brand due to the fact I've had mine for decades.