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Related papers: Pythagorean conics and homothetic triangles

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Given any positive integer n, we prove the existence of infinitely many right triangles with area n and side lengths in certain number fields. This generalizes the famous congruent number problem. The proof allows the explicit construction…

We prove a theorem on the relationships between the lengths of sides of a spherical quadrilateral with three right angles. They are analogous to the relationships in the Lambert quadrilateral in the hyperbolic plane. We apply this theorem…

Metric Geometry · Mathematics 2025-06-30 Marek Lassak

We provide an alternative unified approach for proving the Pythagorean theorem (in dimension $2$ and higher), the law of sines and the law of cosines, based on the concept of shape derivative. The idea behind the proofs is very simple: we…

History and Overview · Mathematics 2023-10-02 Lorenzo Cavallina

It is well known that a triangle with side lengths 3, 4 and 5 is right-angled. Euclid was the first to give a formula for generating other right-angled triangles with integer side lengths. In this text, I present a novel algorithm to…

Number Theory · Mathematics 2022-08-05 Jan Pieter Zwart

In this work, we investigate the following question. Given a Pythagorean triangle BCA, with the right angle at C, let P be a point on the hupotenuse BA; and let D and E be the perpendicular projections of the point P onto the sides BC and…

General Mathematics · Mathematics 2010-07-30 Konstantine Zelator

Recent interest in noncircular trigonometric proofs has underscored the need for alternative methodologies. Jackson and Johnson's 2024 study addresses a longstanding gap in the foundations of trigonometric proofs. Inspired by the work of…

History and Overview · Mathematics 2025-06-10 Shoya Kise , Takesa Uehara , Takashi Shinzato

We develop a rigidity theory for frameworks in $\mathbb{R}^3$ which have two coincident points but are otherwise generic and only infinitesimal motions which are tangential to a family of cylinders induced by the realisation are considered.…

Combinatorics · Mathematics 2016-07-08 Bill Jackson , Viktoria Kaszanitzky , Anthony Nixon

We propose two new proofs of the Pythagorean theorem via area rearrangement arguments starting from very simple geometric configurations. The constructions depend on an angular parameter, each choice of which yields a proof. For specific…

General Mathematics · Mathematics 2025-11-04 Andrés Navas

Pythagorean triples are the positive integer solutions to the Pythagoras equation for right triangles, a2+b2 = c2. They have been studied for many years, many centuries in fact. In this short paper we present a method for computing…

General Mathematics · Mathematics 2023-07-07 James M. Parks

We give a brief historical overview of the famous Pythagoras' theorem and Pythagoras. We present a simple proof of the result and dicsuss some extensions. We follow \cite{thales}, \cite{wiki} and \cite{wiki2} for the historical comments and…

History and Overview · Mathematics 2015-09-23 Manjil P. Saikia

After the introduction, in section 2 we state the well known parametric formulas that describe the entire family of Pythagorean triples. In section 3, we list four well known results from number theory, used later in the paper. in section…

General Mathematics · Mathematics 2009-09-30 Konstantine Zelator

Viviani's theorem states that the sum of distances from any point inside an equilateral triangle to its sides is constant. We consider extensions of the theorem and show that any convex polygon can be divided into parallel segments such…

Metric Geometry · Mathematics 2014-03-24 Elias Abboud

This is a paper about triangle cubics and conics in classical geometry with elements of projective geometry. In recent years, N.J. Wildberger has actively dealt with this topic using an algebraic perspective. Triangle conics were also…

Metric Geometry · Mathematics 2021-01-12 Ruslan Skuratovskii , Veronika Strarodub

It is well known that Heron's theorem provides an explicit formula for the area of a triangle, as a symmetric function of the lengths of its sides. It has been extended by Brahmagupta to quadrilaterals inscribed in a circle (cyclic…

History and Overview · Mathematics 2019-10-21 Paolo Dulio , Enrico Laeng

There are multiple generalisations of the Pythagorean theorem to spherical and hyperbolic geometry. A natural one, involving areas of disks with radii equal to the sides of a proper triangle, was discovered in the hyperbolic case by Maria…

Metric Geometry · Mathematics 2025-09-04 Michaël Maex

Spacetime and internal symmetries can be used to severely restrict the form of the equations for the fundamental laws of physics. The success of this approach in the context of general relativity and particle physics motivates the…

General Relativity and Quantum Cosmology · Physics 2017-02-16 Saurya Das , Gabor Kunstatter

We define operations that give the set of all Pythagorean triples a structure of commutative monoid. In particular, we define these operations by using injections between integer triples and $3 \times 3$ matrices. Firstly, we completely…

Number Theory · Mathematics 2017-12-27 Marco Abrate , Stefano Barbero , Umberto Cerruti , Nadir Murru

We analyze Toponogov's sine theorem for an infinitesimal geodesic triangle ABC on a C^2 regular surface M, which is given in his book [6, Problem 3.7.2] and we provide a generalization of the law of cosines for ABC on M. By replacing in the…

General Mathematics · Mathematics 2020-04-14 Anastasios Zachos

If we label the vertices of a triangle with 1, 2 and 4, and the orthocentre with 7, then any of the four numbers 1, 2, 4, 7 is the nim-sum of the other three and is their orthocentre. Regard the triangle as an orthocentric quadrangle.…

History and Overview · Mathematics 2019-10-09 Richard K. Guy

We provide a new proof of the elementary geometric theorem on the existence and uniqueness of cyclic polygons with prescribed side lengths. The proof is based on a variational principle involving the central angles of the polygon as…

Metric Geometry · Mathematics 2022-12-05 Hana Kouřimská , Lara Skuppin , Boris Springborn