Drawing template in form of circle sector - has centre hole in addition to zones of hole rows, from which extend radial rows of holes for drawing circles and arcs

摘要

The template consists of a plate formed like a quarter of a circle with a millimeter scale on each of its straight edges and with a degree scale on the curve-shaped edge. There are several rows of holes parallel to the straight edges to enable drawing parallel horizontal and vertical lines. There is a central hole outside the area of the hole rows, from which extend several rows of holes, with the distance between the individual holes corresponding to different radii for drawing circles and arcs. There is also provision for drawing circles with very large diameters.