Wenxin Fang was 14 years old when he realized he was fed up with fighting with a flimsy piece of plastic in math class. As an eighth grader at Evergreen Middle School in Redmond, Wash., Fang kept ...

A wide variety of protractors and angle gages are available that vary in construction and application. Angle squares consist of a square with angular graduations along the longest face or hypotenuse.