However, some problems turned out to be difficult or impossible to solve by these means alone, and ingenious constructions using parabolas and other curves, as well as mechanical devices, were found.
Porén, fíxose evidente nalgúns destes problemas a dificultade ou imposibilidade da súa solución, e acháronse enxeñosas construcións usando parábolas e outras curvas, ademais de recursos mecánicos.