| Arthur Schultze - 1901 - 260 σελίδες
...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 the third side and equal to half of it. B a Hyp. In A ABC: AD = DB, AE = EC. To prove 1°. DE II BC. 2°. DE = \BC. Proof.... | |
| Thomas Franklin Holgate - 1901 - 462 σελίδες
...in F. Prove that AB is a mean proportional between AD and AF, ie AD : AB = AB : AF. 3. The straight line which joins the mid-points of two sides of a triangle is parallel to the third side. 4. The straight line drawn through the mid-point of one side of a triangle parallel to a second side... | |
| Arthur Schultze - 1901 - 260 σελίδες
...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 - 1901 - 462 σελίδες
...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 - 1902 - 394 σελίδες
...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.... | |
| Arthur Schultze, Frank Louis Sevenoak - 1901 - 394 σελίδες
...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°.... | |
| Alan Sanders - 1901 - 260 σελίδες
...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... | |
| Edward Brooks - 1901 - 278 σελίδες
...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.);... | |
| Eldred John Brooksmith - 1901 - 368 σελίδες
...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 - 1902 - 248 σελίδες
...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 the sum of the bases.... | |
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