The first six books of the elements of Euclid, in which coloured diagrams and symbols are used instead of letters for the greater ease of learners (1847)
Byrne, Oliver, Whittingham, Charles, 1795-1876, Chiswick Press · London : William Pickering · leaf 167
are equilateral parallelograms; and therefore if a circle be defcribed from the concourfeoi thefe lines with any one of them as radius, it will beinfcribed in the given fquare. (B. 3. pr. 16.) CLE. D. 134 BOOK IF. PROP. IX. PROB.
Euclid's Elements · Geometry
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