Elements of geometry and trigonometry. Revised and adapted to the course of mathematical instruction in the United States (1856)
Legendre, A. M. (Adrien Marie), 1752-1833, Davies, Charles, 1798-1876 · New York : A.S. Barnes · leaf 128
dly. Let it beproposed to divide theline AB into parts pro-portional to the givenlines P, Q, R. ThroughA, draw the indefiniteUne AG ; make AO=P, extremities E and B; and through the points C and D,draw 67, BF, parallel to EB; the line AB will be dividedinto parts AI, IF, FB, proportional to the… … PROBLEM II. To find t^ fijurth proportional to three given lines, A, B, C, Draw the two indefi-nite lines BE, BE, form-ing any angle with eachother. Upon BE takeBA^A, and BB=B;upon BE take BC=G,draw AC; ana throughthe point B, draw BX parallel to AC, and DX will bethe fourth proportional required.…
Geometry · Trigonometry
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
