The circle as generator of Pythagorean triangles

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Issue 1	_
Front matter	_
Table of Contents	_
Article Integers expressible as sums of primes and composites	1
Article Bridges between three remarkable inequalities	8
Article Ein chinesisches Orakel und zyklische Matrizen über dem Körper F2	15
Article Three collinear triangle centres	25
Article A ring-theoretic approach to the double-sidedness of the matrix inverse	30
Article A geometric property of the Möbius transformation	34
Rubric Aufgaben	38
Back matter	_
Issue 2	_
Front matter	_
Table of Contents	_
Article Regular spatial heptagons based on symmetry	45
Article An interesting theorem on circumscribed hexagon	57
Article On quasi-Heronian equable triangles	65
Article The circle as generator of Pythagorean triangles	71
Article Generalizing Lehmer's totient problem	77
Article The generalized Binet formula for k-bonacci numbers	80
Rubric Aufgaben	84
Back matter	_
Issue 3	_
Front matter	_
Table of Contents	_
Article On squares circumscribing quadrangles	89
Article Geometrie der Zahlen	98
Article Equicevian points in a triangle	109
Article A note on rings in which each element is a sum of two idempotents	126
Article Vandermonde's identity proved by complex analysis	128
Rubric Aufgaben	131
Back matter	_
Issue 4	_
Front matter	_
Table of Contents	_
Article A combinatorial approach for computing the determinants of the generalized Vandermonde matrices	137
Article Similarity of quadrilaterals as starting point for a geometric journey to orthocentric systems and conics	148
Article Construction of a quadrilateral from its vertex angles and the diagonal angle	159
Article A new refinement of the Garfunkel-Bankoff inequality	167
Article An improvement of the Weitzenböck inequality	171
Article A generalization of Boole's formula derived from a system of linear equations	173
Rubric Aufgaben	176
Back matter	_

Issue 1

_

Front matter

_

Table of Contents

_

Article Integers expressible as sums of primes and composites

1

Article Bridges between three remarkable inequalities

8

Article Ein chinesisches Orakel und zyklische Matrizen über dem Körper F2

15