 Carol. 4. Parallelograms, or triangles, having an angle in each equal, are in proportion to each other as the rectangles of the sides which are about these equal angles. THEOREM LXXXII. IF a line be drawn in a triangle parallel to one of its sides, it...  Elementary Course of Geometry ... - Pàgina 60per Charles William Hackley - 1847 - 103 pàginesVisualització completa - Sobre aquest llibre
 | Webster Wells - 1886 - 392 pàgines
...i = CFD AE CF ' ' PROPOSITION XIV. THEOREM. 261. A line parallel to one side of a triangle divides the other two sides proportionally. Let DE be parallel to the side BC of the triangle ABC. To prove that — = — . AD AE CASE I. When AB and AD are commensurable. Let AF be a common measure... | |
 | Webster Wells - 1894 - 398 pàgines
..._ DF AB CD' C i F l .1> 1 CASE II. When tlie segments of each side are incommensurable. To prove A Let DE be parallel to the side BC of the triangle ABC. Let AD and DB be incommensurable. AD AE DB EC' Let AD be divided into any number of equal parts, and... | |
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