Can you recreate this?
Can you determine parametric equations for the boundary of the painted region?
It is time to start exercising brains for the start of a new school year!
This file involves two points rotating around a triangle, in opposite directions, one of them moving three times as fast as the other. The segment between those two points is one side of an equilateral triangle. The triangle becomes a "paintbrush" and its trace shades in a region.