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

,

b

,

c

, into a given number of irregularly unequal parts; it is required to divide any other line, C D, into an equal number [p73] ]of parts, bearing to each other the same proportions as the parts of A B, and arranged in the same order.

Draw the two lines parallel to each other, as in the figure.

Join A C and B D, and produce the lines A C, B D, till they meet in P.

Join

a

P,