The 'Compasses Ruler' allows you to draw both perfectly straight lines and exquisite circles. Designers Hyejin-Lee and Youngkwang-Hyun from Hoseo University saw an opportunity to integrate a compass function into the ruler in order to cut down on bulk. Using the ruler, users can accurately draw a circle with a precise diameter without any hassle.
The ruler works by using an anchor tab combined with accurately spaced holes. A pushpin at the end of the ruler can be pressed into the paper to act as an anchor. The sharp end stays within the ruler until the user needs to use the compass function. After choosing the required radius, all you have to do is insert your pencil into a marked hole and smoothly etch out a circle.