Elements of geometry : containing the first six books of Euclid, with a supplement on the quadrature of the circle, and the geometry of solids : to which are added, Elements of plane and spherical geometry (1826)
Playfair, John, 1748-1819, Euclid · Philadelphia : Marot & Walter · leaf 150
therefore the triangle ABD is equian-gular to the trlansle BCE. Wherefore(4.6.), BC : CE : : BD : DA, and con-sequently (16. 6.) BC.DA = BD.CE.Again, because the angle ABE is equalto the angle DBC, and the angle (21.3.)B AE to the angle BDC,the triangle ABEis equiangular to the triangle… … 160 ELEMENTS tained by AB, CD, and AD, BC. Therefore the rectangle, &c.Q. E. D. PROP. E. THEOR. If an arch of a circle be bisected, and from the ex-tremities of the arch, and from the point of bisection^straight lines be drawn to any point in the circumference,the sum of the two lines drawn…
Euclid's Elements · Geometry · Trigonometry
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![An illustration from Divina proportione : opera a tutti glingegni perspicaci e curiosi necessaria oue ciascun studioso di philosophia: prospettiua pictura sculptura: architectura: musica: e altre mathematice: suavissima: sotile: e admirabile doctrina consequira: e delecterassi: co[n] varie questione de secretissima scientia (1509)](https://img.insideoutlibrary.com/img/200/ia-divinaproportion00paci-94-181.webp)
