 | Wooster Woodruff Beman, David Eugene Smith - Geometry, Modern - 1899 - 272 pages
...of a triangle, parallel to another side, bisects the third side. 3. The line joining the mid-points of two sides of a triangle is parallel to the third side. For if not, suppose through the mid-point of one of those sides a line is drawn parallel to the base;... | |
 | Wooster Woodruff Beman, David Eugene Smith - Geometry - 1899 - 412 pages
...Draw a third parallel through the vertex. Then cor. 1 proves it. 3. The line joining the mid-points of two sides of a triangle is parallel to the third side. For if not, suppose through the mid-point of one of those sides a line is drawn parallel to the base... | |
 | Charles Hamilton Ashton - Geometry, Analytic - 1902 - 306 pages
...7, and 8 lie on a line, and find the ratio of their distances from each other. 7410. Show that the line joining the middle points of two sides of a triangle is parallel to the third side and equal to one half of it 11. Show that the diagonals of a square or rhombus are perpendicular to... | |
 | Euclid, Henry Sinclair Hall, Frederick Haller Stevens - Euclid's Elements - 1900 - 330 pages
...sides supplementary, the triangles are equal in area. ON PROP. 39. 10. The straiijht line which joins the middle points of two sides of a triangle is parallel to the third side. 11. If two straight lines AB, CD intersect in O, so that the triangle AOC M equal to the triangle DOB,... | |
 | Alan Sanders - Geometry, Modern - 1901 - 260 pages
...and BC. (?) "" ' '. ^ .•. 0 is equally distant from AB and BCPROPOSITION XXXIX. THEOREM 238. The line joining the middle points of two sides of a triangle is parallel to the third side, and equal to one half of it. « Let DE join the middle points of AB and BC. To Prove DE II to AC, and... | |
 | Eldred John Brooksmith - Mathematics - 1901 - 368 pages
...terms which follow the >•* term ("the remainder after r terms") is less than - ur. \~qx 3. Prove that the straight line joining the middle points of two sides of a triangle is parallel to, and is equal to half the length of the third side. If ABCD be any four.sided figure the three straight... | |
 | Edward Brooks - Geometry, Modern - 1901 - 278 pages
...DF=EC. ButAEDFis&CJ, and DF—AE; hence EC = AE, or AC is bisected at E. COR. — The line which joins the middle points of two sides of a triangle is parallel to the third side, and equal to half of it. For, in the same figure, the line through D \\ to AB passes through E (Th.... | |
 | Edinburgh Mathematical Society - Electronic journals - 1901 - 232 pages
...isotomic conjugate of a side of a triangle is any straight line through the opposite vertex, and that the straight line joining the middle points of two sides of a triangle is its own isotomic conjugate. I have traced the curve for a position of the given point in each of the... | |
 | Arthur Schultze - 1901 - 392 pages
...bisects the other non-parallel side. PROPOSITION XXXIX. THEOREM 147. A line which joins the midpoints of two sides of a triangle is parallel to the third side and equal to half of it. BC Hyp. In A ABC: AD = DB, AE = EC. To prove 1°. DE II BC. 2°. DE = \BC.... | |
 | Arthur Schultze - 1901 - 260 pages
...bisects the other non-parallel side. PROPOSITION XXXIX. THEOREM 147. A line which joins the midpoints of two sides of a triangle is parallel to the third side and equal to half of it. B a Hyp. In A ABC: AD = DB, AE = EC. To prove 1°. DE II BC. 2°. DE = \BC.... | |
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The straight line joining the middle points of two sides of a triangle is parallel to the third side, and equal to half of it. 
