Crossword-Solution: ABCD 4 letters, 147 clues 🏆 scrabble score: 9

The ~ function or ratio of four points abcd on a straight line is the quantity ? : ?, where the segments are to regarded as plus or minus, according to the order of the letters.

Their bigness and Figure may be seen in the second _Figure_ of the seventh _Plate_, which represents about a dozen of them lying upon a plate ABCD, some of which, as a, b, c, d seem’d more regular than the rest, and e, which was a small one, sticking on the top of another, was a perfect _Rhomboeid_ on the top, and had four _Rectangular_ sides.

The Vale it self ABCD, is much of the figure of a Pear, and from several appearances of it, seems to be some very fruitful place, that is, to have its surface all covered over with some kinds of vegetable substances; for in all positions of the light on it, it seems to give a much fainter reflection then the more barren tops of the incompassing Hills, and those a much fainter then divers other cragged, chalky, or rocky Mountains of the Moon.

The anharmonic ratio of four points is sometimes written (_ABCD_), so that [formula] If we take the points in different order, the value of the anharmonic ratio will not necessarily remain the same.

LXXI HOW TO DIVIDE A SQUARE PLACED AT AN ANGLE INTO A GIVEN NUMBER OF SMALL SQUARES _ABCD_ is the given square, and only one vanishing point is accessible.