Keith T. answered 04/08/20
Math, Physics and Some English (Language Arts) Tutoring and Help
If you think of these as two squares, one larger than the other, then side2=36 tells you one side. side2=81 tells you another side. Take a ratio of these.
If you think of these as isosceles right triangles, one larger than the other, then (1/2)*side2=36 for one triangle, and (1/2)*side2=81 for the other. If you take the ratio of these two sides it should agree with the answer for the square. I suspect this works for all polygons.