One‐parameter families of Legendre curves and plane line congruences
One‐parameter families of Legendre curves and plane line congruences
Abstract Families of curves in the Euclidean plane naturally contain singular curves, where the frame of classical differential geometry does not work well. We introduce the notions of one‐parameter family of Legendre curves in the Euclidean plane, congruent equivalence and curvature. Especially, a one‐parameter family of Legendre curves can contain …