ত্রিভুজাকৃতি রুলার

A triangle or set square, as used by engineers or architects to draw straight lines at angles. Variously depicted as a metal, wood, or plastic right triangle with length markings, its hypotenuse to the right.

Commonly applied to a range of disciplines, including art, design, building, architecture, and STEM (science, technology, engineering, and mathematics). May also represent various concepts of angles and measurement.