Henry Ernest Dudeney/Puzzles and Curious Problems/201 - Square and Triangle

Puzzles and Curious Problems by Henry Ernest Dudeney: $201$

Square and Triangle

Take a perfectly square piece of paper,

and fold it as to form the largest possible equilateral triangle.

A triangle in which the sides are the same length as those of the square, as shown in our diagram,

will not be the largest possible.

Of course, no markings or measurements may be made except by the creases themselves.

Sources

• 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Geometrical Problems: Various Geometrical Puzzles: $201$. -- Square and Triangle
• 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Geometrical Problems: Paper Folding Puzzles: $364$. Square and Triangle