Assertion: ellipse's radius | /r/HasProperty | 2 a
Facets:
Source sentences:
text: The radius of curvature at the vertices V 1 , V 2 {\displaystyle V_{1},\,V_{2}} b 2 a {\displaystyle {\tfrac {b^{2}}{a}}}
text: The radius of curvature at the co-vertices V 3 , V 4 {\displaystyle V_{3},\,V_{4}} a 2 b .