Arjun and the geometry galaxy

Arjun entered a silent city made of glowing shapes. A spark appeared, a point, which means an exact position with no size. A shining path formed a line, extending endlessly in both directions. A broken bridge became a line segment, a part of a line with two endpoints, while a laser beam shot as a ray, starting at one point and going endlessly in one direction. The ground was a plane, a flat surface spreading endlessly. Twisting tunnels were curved lines, and a magic gate was a simple closed curve, a curve that starts and ends at the same point. Solving them, Arjun saved the city.