[7] viXra:1908.0550 [pdf] submitted on 2019-08-28 05:10:36
Authors: Volker Thürey
Comments: 3 Pages.
We present subsets of Euclidian spaces in the ordinary plane. Naturally some informations are lost. We provide examples.
Category: Geometry
[6] viXra:1908.0460 [pdf] submitted on 2019-08-23 05:44:28
Authors: Todor Zaharinov
Comments: 11 Pages.
Given three noncollinear points P, B and C, we investigate the construction of the triangle DBC with symmedian point P.
Category: Geometry
[5] viXra:1908.0366 [pdf] submitted on 2019-08-17 17:05:58
Authors: SzÉkely Endre
Comments: 5 Pages. see in "Other instructions"
In this short note an important consequence of my previous paper5 is investigated.
We reinvestigate EUCLID’S 5th postulate
Category: Geometry
[4] viXra:1908.0095 [pdf] submitted on 2019-08-05 10:29:36
Authors: Mark Adams
Comments: 14 Pages.
We consider the volume of the unit edge length Snub Dodecahedron.
Category: Geometry
[3] viXra:1908.0074 [pdf] replaced on 2019-08-12 04:48:42
Authors: Atsushi Koike
Comments: 14 Pages.
According to Pierre Wantzel’s proof of 1837 that the trisection of 60 degree is impossible, because the cubic equation of x^3 - 3x - 1 = 0 had a absence of a rational solution. And his proof reached already a consensus as a general opinion. I learned from Nobukazu Shimeno’s introductory book on complex numbers that Rafael Bombelli got a rational solution x= 4 from the cubic equation x^3 = 15x + 4 based on the Cardinal formula. x^3 = 15x + 4 is x^3 - 15x - 4 = 0, which can be further replaced by x^3 - dx - a = 0. Kentaro Yano, who introduces the trisection of angles, says that the basic equation of x^3 - 3x - 1 = 0 is x^3 - dx - a = 0. In other words, the equation that Rafael Bombelli obtained a rational number solution is the same as the equation of the trisection of the angle. On the other hand, Yano raises x^3 - 3x = 0 as an example when the angle can be divided into three equal parts. Needless to say, x^3 - 3x - 0 = 0 and x^3 - dx - a = 0. Therefore, comparing Rafael Bombelli’s solution and the equation where Yano’s angle trisection is impossible and possible, the equation for angle trisection is x = a. And I found that if x = a = 2 then the solution is obtained at all angles. This paper proves that.
Category: Geometry
[2] viXra:1908.0020 [pdf] submitted on 2019-08-01 10:58:49
Authors: Hiroshi Okumura
Comments: 2 Pages.
We generalize a problem in Wasan geometry involving
the incircle of a triangle.
Category: Geometry
[1] viXra:1908.0004 [pdf] submitted on 2019-08-01 03:51:30
Authors: Antoine Balan
Comments: 1 page, written in english
Here is defined a generalization of connections with help of exterior forms.
Category: Geometry