Fermat's right triangle theorem is, by the Pythagorean theorem, they would form two integer-sided right triangles in which the pair formula_10 gives one leg and the hypotenuse of the smaller triangle and the same pair also forms the two legs of the larger triangle. But if (as Fibonacci asserted) no square congruum can exist, then there can be no two integer right triangles that share two sides in this way. Because the congrua are exactly the numbers that are four times the area of a Pythagorean triangle, and multiplication by four does not change whether a number is square, the existence of a square
Medial triangle of "ABC": the parallel to "AB" through "C", the parallel to "AC" through "B", and the parallel to "BC" through "A". Trilinear coordinates for the vertices of the anticomplementary triangle, X'Y'Z', are given by The name "anticomplementary triangle" corresponds to the fact that its vertices are the anticomplements of the vertices A, B, C of the reference triangle. The vertices of the medial triangle are the complements of A, B, C. Medial triangle Each side of the medial triangle is called a "midsegment" (or "midline"). In general, a midsegment of a triangle is a line segment which joins the midpoints