 | Euclid - 1892 - Liczba stron: 460
...that is, ZY is par1 to BC. QED [A second proof of this proposition may be derived from i. 38, 39.1 3. The straight line which joins the middle points of two sides of a triangle is equal to half the third side. 4. Shew that the three straight lines which join the middle points of... | |
 | Euclid, John Bascombe Lock - 1892 - Liczba stron: 188
...that AB, DC are parallel. So that ABCD is a parallelogram. QED Example ii. The straight line joining the middle points of two sides of a triangle is parallel to the base. Let E, F be the middle points of the sides AC, AB of the triangle ABC; it is required to prove... | |
 | William Chauvenet - 1893 - Liczba stron: 340
...Draw DP parallel to AC. See now Proposition VII. and Proposition XXIX. 29. The straight line joining the middle points of two sides of a triangle is parallel to the third side. (v. Exercise 28.) 30. The three straight lines joining the middle points of the aides of a triangle... | |
 | Seth Thayer Stewart - 1893 - Liczba stron: 262
...xx., Cor. i.) ; .-., e = fand а = dif. of _Ls. 4. The straight line joining the points of bisection of two sides of a triangle is parallel to the third side. Through one point of bisection draw a line | to the third side ; it will pass through the other point... | |
 | George Albert Wentworth, George Anthony Hill - 1894 - Liczba stron: 150
...the shortest line which can be drawn from a point to a straight line. 2. The straight line joining the middle points of two sides of a triangle is parallel to the third side and equal to one-half of it. 3. Two parallel tangents intercept equal arcs on the circumference of... | |
 | Nathan Fellowes Dupuis - 1894 - Liczba stron: 313
...one side of a triangle, parallel to a second side, bisects the third side. And, 2, the line through the middle points of two sides of a triangle is parallel to the third side. 85°. Theorem. — The three medians of a triangle pass through a common point. CF and AD are medians... | |
 | Wooster Woodruff Beman, David Eugene Smith - 1895 - Liczba stron: 344
...through the vertex, th. 27 or cor. 1 proves it. Draw the figure. 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 - 1895 - Liczba stron: 346
...through the vertex, th. 27 or cor. 1 proves it. Draw the figure. 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... | |
 | George Albert Wentworth - 1896 - Liczba stron: 68
...parallel to the base of a triangle, and bisecting one side, bisects the other side also. 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. 190. Cor. 3. The line which is parallel to the bases of a trapezoid... | |
 | University of the South - 1896 - Liczba stron: 148
...whose sides are perpendicular, each to each, are either equal or supplementary. (2) 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. (3) The angle between a tangent and a chord is measured by one-half its... | |
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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 46 INTERCEPTS BY PARALLEL LINES. 
