 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 376 pages
...Hint. — Show that this line coincides with a line drawn / J^ as in §127. A < 129. Exercise. — A straight line joining the middle points of two sides of a triangle is equal to half the third / side. * ty— Hint.— Prove DE = BX, and DE = XC. p/ , 130. Defs. — A... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 374 pages
...B points of two sides of a triangle is parallel to the third /\ side. MA—\N \ 129. Exercise.—A straight line joining the middle points of two sides of a triangle is equal to half the third side. Hint.—Prove DE - BX, and DE = XC. 130. Defs.—A trapezoid is a quadrilateral,... | |
 | Webster Wells - Geometry - 1898 - 250 pages
...parallel to AC. (Sum of 4 at B = 2 rt. A.) MISCELLANEOUS THEOREMS. PROP. XLVII. THEOREM. 130. 77;e line joining the middle points of two sides of a triangle...parallel to the third side, and equal to one-half of it. B Given line DE joining middle points of sides AB and AC, respectively, of A ABC. To Prove DE II BC,... | |
 | John Henry Tanner, Joseph Allen - Geometry, Analytic - 1898 - 458 pages
...square are of equal length, bisect each other, and are at right angles. 10. Prove analytically that the line joining the middle points of two sides of a triangle is parallel to the third side and equal to half its length. 11. Find the locus of the vertex of a triangle whose base is 2 a and the difference... | |
 | John Henry Tanner, Joseph Allen - Geometry, Analytic - 1898 - 458 pages
...in a point ; 38. the perpendicular from each vertex to the opposite sides meet in a point; 39. the line joining the middle points of two sides of a triangle is parallel to the third side. 40. Show that the equation 56 хг + 441 xy - 56 ?/2 - 79 a; - 47 у + 9 = 0 represents the bisectors... | |
 | 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... | |
 | 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...parallel to the third side, and equal to one-half of it. Given line DE joining middle points of sides AB and AC, respectively, of A ABC. To Prove DE II BC,... | |
 | 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 CF... | |
 | 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... | |
 | 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... | |
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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. 
