Euclidean geometry is a special case of the theory of Hilbert spaces; but in order to convince small children of basic facts, e.g. that the line segments from each of the vertices of a triangle to the midpoint of the opposite side are concurrent, I've found I need to resort to synthetic arguments.

Do you know of a comprehensive reference for synthetic euclidean geometry?

Request: Would someone with more points than I please tag this "euclidean-geometry" then scrub this line? Thanks!