Here's a fun way to spend an hour: try re-creating this nomogram using nothing but a compass and a straight edge. I found it really quite satisfying to reverse the addition and multiplication that falls out of the quadratic equations the nomogram can be used to solve. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/8AECE3C0A20A8D993501D2E59349168C/S1757748900001523a.pdf/a-simple-nomogram-for-the-solution-of-quadratic-equations.pdf