Hatfield, Robert Griffith, 1815-1879. [from old catalog] · New York & London, Wiley and Putnam · leaf 71
Fig. 101. 143.—Proposition. A diagonal crossing a parallelogram di-vides it into two equal triangles. Let abed, {Fig. 101,) be agiven parallelogram, and 6 c, a line crossing it diagonally. Then,as a c is equal to 6 d, and a b to c d, the angle at a to the angleat d, the triangle, A, must, according… … 144.—Proposition. Let abed, {Fig. 102,) be a given pa-rallelogram, and 6 c a diagonal. At any distance between a b andc d, draw e f, parallel to ab; through the point, g, the intersectionof the lines, b c and e f, draw h i, parallel to b d. In every paral-lelogram thus divided, the parallelogram,…
Carpentry · Architecture
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
