The whole thing appears to be a 5*13 triangle.
It isn't.
Beware the sleigth-of-hand of the religionists; too
The hypotenuse at 5 across and three down reveals the difference in angle of the altered right triangle. With one the hypotenuse passes just below the lower right corner of the square at 5A3D. with the tricked hypotenuse the line passes through that lower right corner.