 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.  Elements of Geometry - Page 67by Andrew Wheeler Phillips, Irving Fisher - 1896 - 540 pagesFull view - About this book
 | John Henry Tanner, Joseph Allen - Geometry, Analytic - 1898 - 466 pages
...whose vertices are (2, '2), (-7, ~1), and (— 1, 5). Plot the figure. 20. Show analytically that the line joining the middle points of two sides of a triangle is half the length of the third side. 21. A point is 7 units distant from the origin and is equidistant... | |
 | William James Milne - Geometry, Modern - 1899 - 258 pages
...§ 151, FB = DE ; AF = FB = but FB — DE; Why? hence, DE = \AB. Therefore, etc. QED 159. Cor. The line joining the middle points of two sides of a triangle is parallel to the third side. For if the line is not parallel to the third side, suppose a line drawn through D, the middle point... | |
 | William James Milne - Geometry - 1899 - 396 pages
...straight lines drawn between the same two points, which by Ax. 12 is impossible. Consequently, the line joining the middle points of two sides of a triangle is parallel to the third side. Proposition XLIII 160. Draw a trapezoid and a line connecting the middle points of the non.parallel... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...rhomboid when the two diagonals and the included angle are given. Proposition 64. Theorem. 76. The line joining the middle points of two sides of a triangle is parallel to the third side, and is equal to one half the third side. B 57 Conclusion. DE is II to BC, and DE = \ BC. Proof. Draw... | |
 | Webster Wells - Geometry - 1899 - 424 pages
...parallel to AC. (Sum of A at B = 2 rt. A.) A MISCELLANEOUS THEOREMS. PROP. XLVII. THEOREM. 130. 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. Given line DE joining middle points of sides AB and AC, respectively,... | |
 | George Albert Wentworth - Geometry, Modern - 1899 - 272 pages
...equal parts on the transversal AC; that is, the line DE bisects AC. 189. COR. 2. The line which joins the middle points of two sides of a triangle is parallel to the third side, and is equal to half the third side. A line drawn through D, the middle point of AB, II to BC, passes... | |
 | George Albert Wentworth - Geometry, Solid - 1899 - 246 pages
...base of a triangle and bisects one side, it bisects the other side also. 189. The line which joins the middle points of two sides of a triangle is parallel to the third side, and is equal to half the third side. 190. The median of a trapezoid is parallel to the bases, and is... | |
 | George Albert Wentworth - Geometry - 1899 - 500 pages
...equal parts on the transversal AC; that is, the line DE bisects AC. 189. COR. 2. The line which joins the middle points of two sides of a triangle is parallel to the third side, and is equal to half the third side. A line drawn through D, the middle point of AB, II to BC, passes... | |
 | Seymour Eaton - 1899 - 362 pages
...divided by its diagonals are equal to one another. • 3. Prove that the straight line which joins the middle points of two sides of a triangle is parallel to the base. Lesson No. 18 PROPOSITION 40. THEOREM Equal triangles, on equal bases in the same straight line,... | |
 | 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... | |
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