 The line joining the midpoints of two sides of a triangle is parallel to the third side and equal to one-half of it.  Solid Geometry - Page 311by Fletcher Durell - 1904 - 206 pagesFull view - About this book
 | Arthur Schultze - 1901 - 260 pages
...parallel to the base, bisects the other non.parallel side. PROPOSITION XXXIX. THEOREM 147. A line tvhich joins the midpoints of two sides of a triangle is parallel to the third side and equal to half of it. Hyp. \ B In A ABC: To prove 1". DE II BC. 2°. DE = \BC. Proof. Draw FB II AC,... | |
 | Thomas Franklin Holgate - Geometry - 1901 - 462 pages
...the three angles of a triangle is equal to two right angles. § 101. (15) The line-segment joining the mid-points of two sides of a triangle is parallel to the third side and equal to half of it. § 130. (16) If from the mid-point of one side of a triangle there is drawn a... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1901 - 394 pages
...trapezoid, and parallel to the base, bisects the other non.parallel side. PROPOSITION XXXIX. THEOREM 147. A line which joins the midpoints of two sides of a triangle is parallel to and equal to half of the third side. B o Hyp. In A ABC: AD = DB,AE=EC. To prove 1°. DE II BC. 2°.... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1902 - 394 pages
...trapezoid, and parallel to the base, bisects the other non-parallel side. PROPOSITION XXXIX. THEOREM: 147. A line which joins the midpoints of two sides of a triangle is parallel to and equal to half of the third side. Hyp. In A ABC: AD = DB, AE = EC. To prove 1°. DE II BC. Proof.... | |
 | Edward Brooks - Geometry, Modern - 1901 - 278 pages
...and DF—AE; hence EC = AE, or AC is bisected at E. COR. — The line which joins the middle points of two sides of a triangle is parallel to the third side, and equal to half of it. For, in the same figure, the line through D \\ to AB passes through E (Th. I.);... | |
 | Alan Sanders - Geometry, Modern - 1901 - 260 pages
...equally distant from AB and BC. PROPOSITION 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. c Let DE join the middle points of AB and BC. To Prove I)E II to AC, and DE... | |
 | Eldred John Brooksmith - Mathematics - 1901 - 368 pages
...between the same parallels. Use this proposition to show that the straight line joining the middle points of two sides of a triangle is parallel to the third side. 3. Describe a parallelogram equal to a given rectilineal figure, and having an angle equal to a given... | |
 | George Albert Wentworth - Geometry, Solid - 1902 - 248 pages
...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 to half... | |
 | Education - 1902 - 678 pages
...ihe same side of it, are between the same parallels. The straight line which joins the middle points of two sides of a triangle is parallel to the third side. (3) Describe a rectangle equal to a given irregular pentagon. (4) If the square described on one side... | |
 | Alan Sanders - Geometry - 1903 - 396 pages
...on the bisector BF. (§231.) QBD PROPOSITION 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. MC Let DE join the middle points of AB and BC. To Prove DE II to AC, and 7)£... | |
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