Regular stellated Polyhedra or Kepler
... are exact and are they are produced for the first time in this work and in a book for children
that will appears very soon. I have developed these models in order to teach the Geometry in
the high schools. My motivation comes since my teaching duty consist to form the future high
schools teachers. I ...
Integer triangle
An integer triangle or integral triangle is a triangle all of whose sides have lengths that are integers. A rational triangle can be defined as one having all sides with rational length; any such rational triangle can be integrally rescaled (can have all sides multiplied by the same integer, namely a common multiple of their denominators) to obtain an integer triangle, so there is no substantive difference between integer triangles and rational triangles in this sense. Note however, that other definitions of the term ""rational triangle"" also exist: In 1914 Carmichael used the term in the sense that we today use the term Heronian triangle; Somos uses it to refer to triangles whose ratios of sides are rational; Conway and Guy define a rational triangle as one with rational sides and rational angles measured in degrees—in which case the only rational triangle is the rational-sided equilateral triangle.There are various general properties for an integer triangle, given in the first section below. All other sections refer to classes of integer triangles with specific properties.
