@The-Darkin-Blade We found that $$135^{\circ}$$ is the measure of one interior angle of the regular octagon, and $$120^{\circ}$$ is the measure of one interior angle of the hexagon. Since the hexagon angle sits inside the octagon angle, the difference $$135^{\circ}- 120^{\circ}$$ tells us the measure of the $$\textcolor{green}{\text{green}}$$ sliver of an angle in this diagram: