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 61
equal(26.1.), viz. AE to EC, andED fo EB. B O Since, therefore, BD is bisected in E, AB^-fADr»(A. 2.) 2BE«+2AE2; and forthe same reason,CD2+BC«=2BE2-f2EC=2BE>+2AES because EC=AE. Therefore AB+AD3+DC=-j-BC«c=4BE«+4AE^ But 4BE=^=BD«, and 4AE=AC« (2. Cor. 8. 2.) be-cause BD and AC are both bisected… … SLEMZSNTS OP GEOMETRY. BOOS ZXL DEFINITIONS.. A. THE radius of a circle is tke straight line drawn from the centreto the circomference. I. A straight line is said to toucha circle, when it meets thecircle, and being produceddoes not cut it. Circles are said to touch oneanother, which meet, but…
Euclid's Elements · Geometry · Trigonometry
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