The first six books of the elements of Euclid : with a commentary and geometrical exercises ; to which are annexed a treatise on solid geometry, and short essays on ancient geometrical analysis, and the theory of transversals (1861)
Lardner, Dionysius, 1793-1859 · London : Print. for Taylor and Walton · leaf 97
e sum togetherwith half the square of the difference, or to twice the square of half thesum together with twice the square of half the difference (233). Proposition X. Theorem.(259) If a right line (A B) be bisected (in C), and pro-duced to any point (D), the square of thewhole line thus produced… … 78 ELEMENTS OF EUCLID. From the point C draw C E perpendicular to A B and equa\to either CAorCB; join A E, and drawthrough the point E the line E F parallelto A B, and through D, D F parallel toC E ; and because the angles C E F andDFE are equal to two right angles, onaccount of the parallel lines…
Geometry
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