3

Part of 1898 Eotvos Mathematical Competition

Problems(1)

Let $A, B, C, D$ be four given points on a straight line $e$. Construct a square

Source: Eotvos 1898 p3

A, B, C, D

be four given points on a straight line

e

. Construct a square such that two of its parallel sides (or their extensions) go through

A

B

respectively, and the other two sides (and their extensions) go through

C

D