• Journal for History of Mathematics
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• v.33 no.3
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• pp.155-165
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• 2020

Pythagorean theorem is a proposition on the relationship between the lengths of three sides of a right triangle. It is well known that Pythagorean theorem for Euclidean geometry deforms into an interesting form in non-Euclidean geometry. In this paper, we investigate a new perspective that replaces right triangles with 'proper triangles' so that Pythagorean theorem extends to non-Euclidean geometries without any modification. This is seen from the perspective that a rectangle is an equiangular quadrilateral, and a right triangle is a half of a rectangle. Surprisingly, a proper triangle (defined by Paolo Maraner), which is a half of an equiangular quadrilateral, satisfies Pythagorean theorem in many geometries, including hyperbolic geometry and spherical geometry.

• Journal of applied mathematics & informatics
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• v.42 no.2
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• pp.433-444
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• 2024

Our study explores the connection between the Pythagorean theorem and the Fixed-point theorem in metric spaces. Both of which center around the concepts of distance transformations and point relationships. The Pythagorean theorem deals with right triangles in Euclidean space, emphasizing distances between points. In contrast, fixed-point theorems pertain to the points that remain unchanged under specific transformations thereby preserving distances. The article delves into the intrinsic correlation between these concepts and presents a novel study in Euclidean metric spaces, examining the relationship between contraction mapping and Pythagorean Right Triangles. Practical applications are also discussed particularly in the context of image compression. Here, the integration of the Pythagorean right triangle paradigm with contraction mappings results in efficient data representation and the preservation of visual data relation-ships. This illustrates the practical utility of seemingly abstract theories in addressing real-world challenges.

• The Mathematical Education
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• v.41 no.2
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• pp.227-231
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• 2002

The Pythagorean theorem and Pythagorean triple are well known. We know some Pythagorean triples, however we don't Cow well that every natural number can belong to some Pythagorean triple. In this paper, we show that every natural number, which is not less than 2, can be a length of a leg(a side opposite the acute angle in a right triangle) in some right triangle, and list some Pythagorean triples.

• East Asian mathematical journal
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• v.31 no.4
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• pp.459-481
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• 2015

In this study, we investigated whether the theorem is established even if we replace a 'square' element in the Euclidean proof of the Pythagorean theorem with different figures. At this time, we used different figures as equilateral, isosceles triangle, (mutant) a right triangle, a rectangle, a parallelogram, and any similar figures. Pythagorean theorem implies a relationship between the three sides of a right triangle. However, the procedure of Euclidean proof is discussed in relation between the areas of the square, which each edge is the length of each side of a right triangle. In this study, according to the attached figures, we found that the Pythagorean theorem appears in the following three cases, that is, the relationship between the sides, the relationship between the areas, and one case that do not appear in the previous two cases directly. In addition, we recognized the efficiency of Euclidean proof attached the square. This proving activity requires a mathematical process, and a generalization of this process is a good material that can experience the diversity and rigor at the same time.

• School Mathematics
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• v.4 no.3
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• pp.401-413
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• 2002

The Pythagorean theorem is one of the most important theorem which appeared in school mathematics. Allowing our pupils to rediscover it in classroom, we must know how this theorem was discovered and proved. Further, we should recompose that historical knowledge to practical program which might be suitable to them So, firstly this paper surveyed the history of mathematics on discovering the Pyth-agorean theorem. This theorem was known to many ancient civilizatons: There are evidences that Babylonian and Indian had the knowledges on the relationship among the sides of a right triangle. In Zhoubi suanjing, which was ancient Chinese text book, was the proof of the Pythagorean theorem in special case. And then this paper proposed a teaching program that is composed following five tasks : 1) To draw up squares on geo-board that are various in size and shape, 2) To invent squares that are n-times bigger than a given square, 3) Discovering the Pyth-agorean theorem through the previous activity, 4) To prove the Pythagorean theorem in special case, 5) To prove the Pythagorean theorem in general case.

• Journal for History of Mathematics
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• v.34 no.6
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• pp.205-223
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• 2021

It has been argued that as for the origin of the Pythagorean theorem, the theorem had already been discovered and proved before Pythagoras, and the historical records of ancient mathematics have confirmed various uses of this theorem. The purpose of this study is to examine the relevance of its name caused by Eurocentrism and the weakness of its use in Korean school mathematics and to seek improvements from a critical point of view. To this end, the Pythagorean theorem was reviewed from the perspectives of the history of mathematics and mathematics education. In addition, its name in relation to objective mathematical contents regardless of any specific civilization and its use as a starting point for teaching the theorem in school mathematics were suggested.

• Journal for History of Mathematics
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• v.18 no.3
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• pp.25-38
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• 2005

We briefly survey the history of Chinese mathematics which concerns the resolution of right triangles. And we analyse the problems Yucigugosulyodohae(劉氏勾股述要圖解) which is the mathematical book of Chosun Dynasty and contains the 224 problems about right triangles only. Among them, 210 problems are for resolution of right triangles. We also present the methods for generating the Pythagorean triples and constructing polynomial equations in Yucigugosulyodohae which are needed for resolving right triangles.

• Journal for History of Mathematics
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• v.15 no.1
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• pp.43-56
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• 2002

Hong, Jung-Ha(1684-\ulcorner ) explained 78 problems which look for the length of right triangle satisfying the given conditions by the Pythagorean theorem or the ratio of similarity in the chapter ‘Goo-Go-Hoh-Eun-Moon’of the 5th volume of his book Goo-Ill-Jeep. Most questions are formulated by equations of degree 2, 3, 4 which mostly have rational number solutions and part of the equations are expressed by counting stick. The explanation of each question describes the procedure to make the equation in detail, but only presents the solution with a few steps to solve.

• East Asian mathematical journal
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• v.28 no.4
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• pp.419-433
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• 2012

In this paper, by using the inductive method, recurrence relation, the unit circle, circle to inscribe a right-angled triangle, formula of multiple angles, solution of quadratic equation and Fibonacci numbers, we study various problem solving methods to find pythagorean triple.

• Journal for History of Mathematics
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• v.30 no.4
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• pp.221-232
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• 2017

In this paper, we discuss how ancient Egyptians find out the area of the circle based on $\ll$Ahmose Papyrus$\gg$. Vogel and Engels studied the quadrature of the circle, one of the basic concepts of ancient Egyptian mathematics. We look closely at the interpretation based on the approximate right triangle of Robins and Shute. As circumstantial evidence for Robbins and Shute's hypothesis, Egyptians prior to the 12th dynasty considered the perception of a right triangle as examples of 'simultaneous equation', 'unit of length', 'unit of slope', 'Egyptian triple', and 'right triangles transfer to Greece'. Finally, we present a method to utilize the squaring the circle by ancient Egyptians interpreted by Robbins and Shute as the dynamic symmetry of Hambidge.