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 48
nthe opposite sides of AB,, makewith it at the point A the adja-cent angles equal to two right an-gles; therefore CA is in the samestraight line (14. 1.) with AG;for the same reason, AB and AHare in the same straight line.Now because the angle DBC isequal to the angle FBA, each ofthem being a right… … ^ ELEMENTS angle FBC, therefore the base AD is equal (4. 1.) to the base FC,and the triangle ABDtothe triangle FBC. But the parallelogramPL is* double (41. 1.) of the triangle ABD, because (hey are uponthe same base, BD, and between the same parallels, BD, AL; and thesquare GB is double ol the…
Euclid's Elements · Geometry · Trigonometry
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