postulado 60, poligonos concavos ordenados 27
The length of the diagonal of congruent diamonds or the congruent rhomboids that divides a polygon data ordered concave ( m, mm, n ) m greater than n, n greater or equal to one, is equal to the length of the side than the congruent rectangles or the congruent rhomboids that were divided into a rectangle and a diamond shape of order ( m, 41 m; m greater or equal to two, and through this mentally is supposed that is built the polygons concave ordered.