Forum Geometricorum
Volume 18 (2018)

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42. Francisco Javier Garcia Capitan, Circumconics with Asymptotes Making a Given Angle, 367—370.

41. Roger C. Alperin, Pedals of the Poncelet pencil and Fontené points, 361--365.

40. Nikolaos Dergiades and Tran Quang Hung, Simple proofs of Feuerbach's Theorem and Emelyanov's Theorem, 353--359.

39. Floor van Lamoen, Orthopoles and variable flanks, 349--351.

38. Paris Pamfilos, Self-pivoting convex  quadrangles, 321--347.

 37. Şahlar Meherrem, Gizem Günel Açıksöz, Serenay Şen, Zeynep   Sezer, and Güneş Başkes, Geometric inequalities in pedal quadrilaterals, 309-320.

 36. Floor van Lamoen, A synthetic proof of the equality of iterated Kiepert triangles K(ϕ, ψ) = K( ψ, ϕ), 307-308.

 35. Omid Ali Shahni Karamzadeh, Is the mystery of Morley's trisector theorem resolved? 297-306.

 34. John Donnelly, A model of nowhere geodesic plane geometry in which the triangle inequality fails everywhere, 275-296.

 33. John Donnelly, A model of continuous plane geometry that is nowhere geodesic, 255-273.

 32. Robert Bosch, A new proof of Pitot theorem by AM-GM inequality, 251-253.

 31. Martina Stepanova, New constructions of triangle from α, b-c, t_A,


 30. Tran Quang Hung, A construction of the golden ratio in an arbitrary triangle, 239-244.

 29. Blas Herrera, Algebraic equations of all involucre conics in the configuration of the c-inscribed equilateral triangles of a triangle,


 28. Mohammad K. Azarian, “A Study of Risāla al-Watar wa’l Jaib” (The Treatise on the Chord and Sine): Revisited, 219-222.

 27. Nikolaos Dergiades, Parallelograms inscribed in convex quadrangles, 203-218.

 26. Purevsuren Damba and Uuganbaatar Ninjbat,  Side Disks of a spherical great polygon,  195-201.

 25. Mihály Bencze and Marius Drăgan, The Blundon theorem in an Acute Triangle and Some Consequences, 185-194.

 24. Paris Pamfilos, Rectangles circumscribing a quadrangle, 161-184.

23. Hiroshi Okumura and Saburou Saitoh, Harmonic mean and division by zero, 155-159.

22. Mark Shattuck, A geometric inequality for cyclic quadrilaterals, 141-154.

21. Eugen J. Ionaşcu, The ``circle" of Apollonius in Hyperbolic Geometry, 135-140.

20. Michel Bataille, Constructing a triangle from two vertices and the symmedian point, 129-133.

19. Nicholas D. Brubaker, Jasmine Camero, Oscar Rocha Rocha, Roberto Soto, and Bogdan D. Suceavă, A curvature invariant inspired by Leonhard Euler's inequality R ≥ 2r, 119-127.

18. Gábor Gévay, An extension of Miquel's six-circles theorem, 115-118.
17. (Retracted) Sándor Nagydobai Kiss, On the cyclic quadrilaterals with the same Varignon parallelogram, 103-113.

16. Hiroshi Okumura and Saburou Saitoh, Remarks for the twin circles of Archimedes in a skewed arbelos, 99-102.

15. Gerasimos T. Soldatos, A toroidal approach to the doubling of the cube, 93-97.

14. Paris Pamfilos, Parabola conjugate to rectangular hyperbola, 87-92.
13. Robert Bosch, A new proof of Erdős-Mordell inequality, 83-86.

12. Francisco Javier Garcıa Capitán, A family of triangles for which two specific triangle centers have the same coordinates, 79-82.

11. Li Zhou, Primitive Heronian triangles with integer inradius and exradii, 71-77.

10. Apostolos Hadjidimos, Twins of Hofstadter elements, 63-70.

9. Michel Bataille, On the extrema of some distance ratios, 57-62.

8. Giovanni Lucca, Integer sequences and circle chains inside a circular segment, 47-55.

7. Lubomir P. Markov, Revisiting the infinite surface area of Gabriel's horn, 45-46.

6. Hiroshi Okumura, A remark on the arbelos and the regular star polygon, 43-44.

5. Manfred Pietsch, Two hinged regular n-sided polygons, 39-42.

4. Samuel G. Moreno and Esther M. Garcıa--Caballero, Irrationality of √2: Yet another visual proof, 37-38.

3. C. E. Garza-Hume, Maricarmen C. Jorge, and Arturo Olvera, Areas and shapes of planar irregular polygons, 17-36.

2. Carl Eberhart, Revisiting the quadrisection problem of Jacob Bernoulli, 7-16.

1. Stefan Liebscher and Dierck-E. Liebscher, The relativity of conics and circles, 1-6.