To get you started on the algebra, it might help to note that the mathematical curves used to represent Mondrian were

$$\begin{eqnarray} y&=&0.5\tan(1.2(x-1)) - 0.3\\ 0.5(y-1.5)^2+x^2 &=& 0.6\\ (y-1.6)^2+0.25(x\pm 0.3)^2&=& 0.01\\ y&=&-8(x-1)^3\\ y&=&-2x-2\\ y&=&-4x -2\\ y&=&5x-2 \\ y&=&3x-2 \end{eqnarray}$$