Concurrent Segments in a Tetrahedron â Applications of Cevaâs and Carnotâs Theorems
Journal for geometry and graphics, Tome 26 (2022) no. 2, pp. 289-3
Cevas theorem is about concurrence of three segments on a triangle with an affine ratio. Among the several theorems named after him, we are interested in Carnots theorem that relates the concurrence of two segments in a skew quadrilateral in space, again, with an affine ratio. First, we apply these theorems to obtain a theorem on the concurrence of seven segments in a tetrahedron. Secondly, we show that the Steiner-Routh theorem implies Carnots theorem, and obtain the volumes of the two parts of a tetrahedron separated by a planar quadrilateral. Thirdly, we consider a special case of Carnots theorem (or an extension of Varignons theorem) to determine when four points on a skew quadrilateral are to form a parallelogram. Finally, we give a new characterization of the centroid of a tetrahedron.
Classification :
51M04, 51M25
Mots-clés : Tetrahedron, Ceva's theorem, Carnot's theorem, concurrence, affine ratio, centroid
Mots-clés : Tetrahedron, Ceva's theorem, Carnot's theorem, concurrence, affine ratio, centroid
@article{JGG_2022_26_2_JGG_2022_26_2_a6,
author = {H. Katsuura},
title = {Concurrent {Segments} in a {Tetrahedron} \^a {Applications} of {Ceva\^as} and {Carnot\^as} {Theorems}},
journal = {Journal for geometry and graphics},
pages = {289--3},
year = {2022},
volume = {26},
number = {2},
url = {http://geodesic.mathdoc.fr/item/JGG_2022_26_2_JGG_2022_26_2_a6/}
}
TY - JOUR AU - H. Katsuura TI - Concurrent Segments in a Tetrahedron â Applications of Cevaâs and Carnotâs Theorems JO - Journal for geometry and graphics PY - 2022 SP - 289 EP - 3 VL - 26 IS - 2 UR - http://geodesic.mathdoc.fr/item/JGG_2022_26_2_JGG_2022_26_2_a6/ ID - JGG_2022_26_2_JGG_2022_26_2_a6 ER -
H. Katsuura. Concurrent Segments in a Tetrahedron â Applications of Cevaâs and Carnotâs Theorems. Journal for geometry and graphics, Tome 26 (2022) no. 2, pp. 289-3. http://geodesic.mathdoc.fr/item/JGG_2022_26_2_JGG_2022_26_2_a6/