Curvature
Curvature of Plane Curves
curvature of curves 010819.pdf
"If a Circle touches any curve on its concave side, in any given point, and if it may be of such magnitude that no other
tangent circle be inscribed in the angle of contact at that point, that Circle should be the same Curvature as the curve is of,
at the point of contact".
Isaac Newton
Newton Curvature.pdf