If the center of curvature of the lower arc were really on the line of symmetry, there would be no corner at the bottom. In fact, it looks as if the center of curvature of the lower arc coincides with the center of curvature of the upper arc on the other side, which is rather neat.
If the center of curvature of the lower arc were really on the line of symmetry, there would be no corner at the bottom. In fact, it looks as if the center of curvature of the lower arc coincides with the center of curvature of the upper arc on the other side, which is rather neat.