174.--THE SQUARES OF BROCADE.

[Illustration: Diagram 1]

So far as I have been able to discover, there is only one possible

solution to fulfil the conditions. The pieces fit together as in Diagram

1, Diagrams 2 and 3 showing how the two original squares are to be cut.

It will be seen that the pieces A and C have each twenty chequers, and

are therefore of equal area. Diagram 4 (built up with the dissected

square No. 5) solves the puzzle, except for the small condition

contained in the words, "I cut the _two_ squares in the manner desired."

In this case the smaller square is preserved intact. Still I give it as

an illustration of a feature of the puzzle. It is impossible in a

problem of this kind to give a _quarter-turn_ to any of the pieces if

the pattern is to properly match, but (as in the case of F, in Diagram

4) we may give a symmetrical piece a _half-turn_--that is, turn it

upside down. Whether or not a piece may be given a quarter-turn, a

half-turn, or no turn at all in these chequered problems, depends on the

character of the design, on the material employed, and also on the form

of the piece itself.

[Illustration: Diagram 2]

[Illustration: Diagram 3]

[Illustration: Diagram 4]

[Illustration: Diagram 5]

Amusements in Mathematics · 第 682 / 970 题