| William James Milne - Geometry - 1899 - 398 pages
...two 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... | |
| 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... | |
| George Albert Wentworth - Geometry, Plane - 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... | |
| 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... | |
| 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;... | |
| Charles Hamilton Ashton - Geometry, Analytic - 1902 - 310 pages
...problems 6, 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... | |
| 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
...from AC 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... | |
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