JF Ptak Science Books Quick Post
I don't encounter "love" and "Euclid" together very often outside of "I Heart Euclid" tee shirts and mugs and such, but what we have below is a satirical/comical proof of the existence of love (within limited contexts) employing a parallelogram and Euclid. The cartoon (from Punch, printed in London in 1879) has nothing really to do with Euclid, though it does lay the 13th book, proposition 1, of his Elements ("If a straight line is cut in extreme and mean ratio, then the square on the greater segment added to the half of the whole is five times the square on the half") on top of things. The court (as in "courting") for the two players actually doesn't look much like a parallelogram, though if it is a standard tennis court, it must be a rectangle and so a parallelogram, the odd shape a result of a cartoon drawn in probably two hours with a little bit of distortion in the perspective. The lady is coy-ish, and Mr. Punch--dressed in a heart-drench tunic and clearly removed from our mortal coil--is definitely feeling something for the young lady, as we can plainly see with the various lines connecting them. And of course Mr. Punch is clearly a prize in anyone's estimation.
I guess some of this must have to do with the contemporary tennis craze, as this issue of Punch hosts a number of cartoons regarding seemingly everyone at play with tennis. that part of the point tally is the score "love", the cartoonist didn't have to go far to spread Euclid on top of the geometric situation.