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 85
Thus: the right angled parallelogram HH[be contained by the fides ———^ and —or it may be briefly defignated by is faid to If the adjacent fides are eq^ual; i. e. -——— ^ ^ then —i^»^-« . - which is the expreflion for the redtangle under is a fquare, and is equal to J and - or - or 52 BOOK II.…
Euclid's Elements · Geometry
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