The Elements of Perspective / arranged for the use of schools and intended to be read in connection with the first three books of Euclid

by John Ruskin

R′ or

a

X on the opposite side of the line

a

V, the line joining R′ M or X N will equally cut

a

V in

b

.

The points M and N are called the “Dividing-Points” of the original line A B ([Fig. 12.]), and we resume the results of these corollaries in the following three problems.