The American house-carpenter; a treatise on the art of building, and the strength of materials (1873)
Hatfield, R. G. (Robert Griffith), 1815-1879 · New York : J. Wiley · leaf 76
143.—Proposition. A diagonal crossing a parallelogram di-vides it into two equal triangles. Let abed, (Fig. 101,) be agiven parallelogram, and b c, a line crossing it diagonally. Then,as a c is equal to b d, and a b to c d, the angle at a to the angleat d, the triangle, A, must, according to Art.… … Fig. 102. 144.—Proposition. Let abed, (Fig. 102,) be a given pa«rallelogram, and b c a diagonal. At any distance between a b andc d, draw e /, parallel to a b ; through the point, g, the intersectionof the lines, b c and e/, draw h t, parallel to b d. In every paral-lelogram thus divided, the…
Carpentry · Architecture
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Works. Popular edition.] 2 series (1886)](https://img.insideoutlibrary.com/img/200/bl-bl_003191336_9-317-1.webp)