I was on holiday in Greece until yesterday evening, so have only just come to this. At first, I was impressed that anyone could make a puzzle out of the geometrical configuration (one I know very well, as I have given masterclasses about it) and I looked forward to drawing the details. However, when I got around to this , I starting doubting the accuracy of the puzzle..
The preamble asks us to draw the Euler line precisely. I assume that the triangle in question has three Xs as vertices. Then it is straightforward to identify four significant points on the line. The centroid (usually denoted by G) is just to the the second E in A*****. The orthocentre (usually H) is the G in N*********. The circumcentre (usually O) is more or less the P of C*****. The nine-point centre (usually N) is at a grid point in the square consisting of the letters P,E,L,L reading anticlockwise (another mathematician); it is the midpoint of HO.
So I know precisely (as the instruction demands) where the Euler line is, provided that I have the triangle right. But this line is NOTparallel to a side of the triangle, and it does NOT pass through the letters of EULER which are equally spaced in the grid. However, the nine Os on the nine point circle are the midpoints of the sides, the feet of the altitudes, and the midpoints of the segments joining the orthocentre to the vertices. All of that matches up nicely, so I do not think that I have the wrong base triangle. But if I do represent the Euler line precisely, I will be marked wrong, as I am pretty sure that we are meant to join up the letters of Euler.
I can only think that I am wrong in assuming that the base triangle has Xs as vertices! But then everything else fits together so well.
(Incidentally, the nine point circle is not tangential to the side of the triangle, as someone was claiming: it never is. But that is irrelevant. However, I thought that Longchamps was a nice touch.)