This special issue of the Math Forum's weekly newsletter highlights interesting conversations taking place during December of 1998 on Internet math discussion groups.
Proofs are simply too long and too overwhelming for students.
My piano teacher always amazed me by playing complicated Bach pieces at sight. Whereas when I played at sight, each note involved finger juggling and thinking. Polya wrote about the value of teaching mathematical ideas using repetition but with variation, and pointed to the composers for examples. Perhaps sight-reading is another example where we could learn from the composers. The projective invariance implies that the formulae are the same in all systems of trilinear coordinates, so in particular they are the same in barycentrics or orthogonal trilinears.