 | Edinburgh Mathematical Society - Electronic journals - 1897 - 316 pages
...assumes only Euclid, I. 43, and its converse, with the well-known deductions, " the line joining the mid points of two sides of a triangle is parallel to the third side," and " the mid point of one diagonal of a parallelogram is also the mid point of the other." The proof given... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 374 pages
...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,... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1897 - 376 pages
...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... | |
 | Webster Wells - Geometry - 1898 - 284 pages
...line parallel to AC. (Sum of A at B = 2 rt. A.) MISCELLANEOUS THEOREMS. V PROP. XL VII. THEOREM. 130. The line joining the middle points of two sides of...triangle is 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... | |
 | 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 is 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... | |
 | Webster Wells - Geometry - 1899 - 424 pages
...line 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...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, of A ABC. To... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...construct a 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, Modern - 1899 - 258 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... | |
 | 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, 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 equal... | |
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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. 
