Hyperbolic paraboloids are solutions of the equation \(\frac{x^2}{a^2}+\frac{y^2}{b^2}-\frac{z^2}{c^2}=1\) with \(a,b,c\) positive reals. Many sections of paraboloids are parabola for example all sections paralell to the \(xz\) - or \(yz\) -plane.