Menaechmus's cube duplication



To construct a line of length 23\sqrt[3]{2}.

Deaw the parabola with equation y=x2y = x^{2}.
Draw the parabola with equation y2=2xy^{2} = 2x.
These curves meet at PP.

The xx-coordinate of PP is 23\sqrt[3]{2}.

Of course the construction does not satisfy the compass and straight edge rules.