| Euclid, John Casey - Euclid's Elements - 1885 - 340 pages
...Exercises. 1. Triangles and parallelograms of equal bases and altitudes are respectively equal. 2. The right line joining the middle points of two sides of a triangle is | arallel to the third ; for the medians from the extremities of the base to these points will each... | |
| Webster Wells - Geometry - 1886 - 392 pages
...trapezoid form a quadrilateral two of whose angles are right angles. PROPOSITION XLIV. THEOREM. 130. The straight line joining the 'middle points of two...parallel to the third side and equal to one-half of it. A In the triangle ABC, let B' be the middle point of AB and C" of AC. To prove that B'C' is parallel... | |
| George Albert Wentworth - Geometry, Analytic - 1886 - 334 pages
...— 3) ? 52. Prove that the diagonals of a square are perpendicular to each other. 53. Prove that the line joining the middle points of two sides of a triangle is parallel to the third side. 55. Show that the three points (3a, 0), (0, 3b), (a, 2li) are in a straight line. 56. Show that the... | |
| George Albert Wentworth - 1886 - 322 pages
...— 3) ? 52. Prove that the diagonals of a square are perpendicular to each other. 53. Prove that the line joining the middle points of two sides of a triangle is parallel to the thh-d side. 5.5. Show that the three points (3a, 0), (0, 3i), (a, 2K) are in a straight line. 56. Show... | |
| George Bruce Halsted - Geometry - 1886 - 394 pages
...second side, it will bisect the third side ; and, inversely, the sect joining the midpoints of any two sides of a triangle is parallel to the third side and equal to half of it. 233. Three or more lines which intersect in the same point are said to be Concurrent. 234.... | |
| William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...one-half the base. Suggestion. Draw DF 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 sides of a triangle... | |
| William Chauvenet, William Elwood Byerly - Geometry - 1887 - 332 pages
...one-half the base. Suggestion. Draw DF parallel to A C. 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 sides of a triangle... | |
| George Albert Wentworth - Geometry, Analytic - 1886 - 262 pages
...that the diagonals of a square are _L to each other. 53. Prove that the line joining the middle point of two sides of a triangle is parallel to the third side. 54. What is the geometric meaning of the equation 55. Show that the three points (3 a, 0), (0, Bb),... | |
| John Bascombe Lock - Forces and couples - 1888 - 278 pages
...middle point of one of the sides of another piece of cardboard. Shew that their cGs are superposed. The line joining the middle points of two sides of a triangle is parallel to the third side of the triangle and is bisected by the line joining the middle point of the third side to the opposite... | |
| George Albert Wentworth - 1889 - 276 pages
...the angle, and every point not in the bisector is unequally distant from the sides. 70. Theorem. The line joining the middle points of two sides of a triangle is parallel to the third side and equal to half of the third side. 71. Theorem. A straight line drawn parallel to the base of a triangle, bisecting... | |
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