Little explorations with HP calculators (no Prime)

[pier4r]

Quote:Brilliant.org

This one defeated me at the moment. My rusty memory about mathematical relations did not help me. At the end, having the hp50g, I tried to use some visual observations to write down the cartesian coordinates of the points defining the inner square, or observing the length of the sides, so if the side of the inner square is 2r so the sides of the triangle are "s+2r" and "s" from which one can say that "s^2+(s+2r)^2=1" . This plus the knowledge that 4 times the triangles plus the inner square add up to 1 as area. Still, those were not enough for a solution (with or without the hp50g). I end in too ugly/tedious formulae.