EntityQ3526990· pop 8· linked from 8 articlesEuler's theoremSign in to savetheorem in the mathematical field of differential geometryConnectionsprincipal curvatureEntityLeonhard EulerEntityInternational Standard Book NumberEntitycurveEntitydifferential geometryEntityEuclidean spaceEntityperpendicularityEntityunit vectorEntitynormalEntitycurvatureEntityEarth radiusEntitytangent vectorEntityMichael SpivakEntitydifferential geometry of surfacesEntityLuther P. EisenhartEntityDupin indicatrixEntityCategoriesDifferential geometry of surfacesLeonhard EulerTheorems in differential geometry