Davies, Charles, 1798-1876 · New York and Chicago, A. S. Barnes and company · leaf 37
and AD=BC then will these sides be parallel, and thefigure will be a parallelogram. For, draw the diagonal BD. Then, the two triangles A BI)BDC, have all the sides of the one equal to all the sides ofthe other, each to each : therefore, the two triangles are equal(Th. viii); hence, the angle ADB,… … THEOREM XXV.If two opposite sides of a quadrilateral are equal and parallel tlw remaining sides will also be equal and parallel, and the figurewill be a varallelogram. Let ABCD be a quadrilateral, havingthe sides A B, CD, equal and parallel:then will the figure be a parallelogram. For, draw the…
Geometry · Plane trigonometry
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
