An oval is a curve resembling a squashed Circle but, unlike the Ellipse, without a precise mathematical definition. The word oval derived from the Latin word ``ovus'' for egg. Unlike ellipses, ovals sometimes have only a single axis of reflection symmetry (instead of two).
Ovals can be constructed with a Compass by joining together arcs of different radii such that the centers of the arcs lie on a line passing through the join point (Dixon 1991). Albrecht Dürer used this method to design a Roman letter font.
See also Cartesian Ovals, Cassini Ovals, Egg, Ellipse, Ovoid, Superellipse
References
Critchlow, K. Time Stands Still. London: Gordon Fraser, 1979.
Cundy, H. and Rollett, A. Mathematical Models, 3rd ed. Stradbroke, England: Tarquin Pub., 1989.
Dixon, R. Mathographics. New York: Dover, pp. 3-11, 1991.
Dixon, R. ``The Drawing Out of an Egg.'' New Sci., July 29, 1982.
Pedoe, D. Geometry and the Liberal Arts. London: Peregrine, 1976.