Original text - English - three vertices of a regular heptagon can be...

three vertices of a regular heptagon can be connected to produce four distinct species of triangles, three of them isosceles and the fourth scalene.The latter, which we shall call ''the Heptagonal Triangle'', is uniquely characterized by verticles whose angles belong to a geometric progression with a common ratio of 2.A survey of the properties of this triangle will provide a better understanding of the regular polygon from which it is derived.