Lemma
MediumGeometrical puzzles
H. E. Dudeney, Amusements in Mathematics (1917) No. 186 · Puzzles · Geometrical puzzles

The Clothes Line Puzzle

A boy tied a clothes line from the top of each of two poles to the base of the other. He then proposed to his father the following question. As one pole was exactly seven feet above the ground and the other exactly five feet, what was the height from the ground where the two cords crossed one another?

~8 minWritten answer · compare with the solution

H. E. Dudeney, Amusements in Mathematics (1917) · No. 186

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