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 144
BOOK THE FOURTH. 125 … Hence the centre and (420) The areas of the three triangles BDC, C D A, and A D B, arerespectively equal to half the rectangles under the radius of the in-scribed circle and the sides B C, C A, and B A of the given triangle.Hence the area of the given triangle is equal to the rectangle underthe…
Geometry
Internet Archive · Public Domain Mark 1.0. Free to use for anything.
