Ruskin, John; Cook, Edward T. [Editor]: The works of John Ruskin: The elements of drawing. The elements of perspective. And the laws of Fésole (London, 1904)

PROBLEM XIII

TO DRAW A SQUARE, GIVEN IN MAGNITUDE, WITHIN A
LARGER SQUARE, GIVEN IN POSITION AND MAGNITUDE;
THE SIDES OF THE TWO SQUARES BEING PARALLEL

A B

F


LET A B, Fig. 84, be the sight-magnitude of the side of the
smaller square, and A c that of the side of the larger square.
Draw the larger square. Let D E F G be the square so
drawn.
Join E G and D F.
On either D E or D G set off, in perspective ratio, D H
equal to one half of B c. Through H draw H K to the
vanishing-point of D E, cutting D F in i and E G in K.
Through i and K draw i M, K L, to vanishing-point of
D G, cutting D F in L and E G in M. Join L M.
Then i K L M is the smaller square, inscribed as required.^
* If either of the sides of the greater square is parallel to the plane

E F


D H G
35

of the picture, as D G in Fig. 35, D G of course must be equal to A c,
and D H equal to and the construction is as in Fig 35.

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