Hello. I'm trying to construct an object that contains a perfect hexagram (perfect as in all extruding points are equidistant from center), like the Star of David. I need to be mathematically accurate with my dimensions, and I need help.

If inscribed in a rectangle, what would be the generalized ratio of the rectangle's length to its width. For example, an equilateral triangle's excribed rectangle has a ratio of : So what would it be for a hexagram?