 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1896 - 574 pages
...drawn in PQ through B, it is perpendicular to PQ. § 530 QED PROPOSITION XIV. THEOREM 562. If' a plane is perpendicular to one of two parallel lines, it is perpendicular to tl1e other. GIVEN — the parallel lines AB and DE and the plane MN perpendicular to AB at B. To PROVE... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...that can be drawn through C II to AB. (See Ax. 21.) QED Proposition 25. Theorem. 35. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also. B Proof. Through G, the point of intersection of AB and EF, draw HK _L to AB. Then HK is II to... | |
 | Harvard University - Geometry - 1899 - 39 pages
...angles on the same side of the secant line is equal to two right angles. Corollary III. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other. THEOREM XIX. The sum of the three angles of any triangle is equal to two right angles. THEOREM XX.... | |
 | George Albert Wentworth - Geometry - 1899 - 496 pages
...straight line are parallel to each other. PARALLEL LINES. PROPOSITION XI. THEOREM. 107. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also. B 0 X -B .ZV § 104 Hyp. § 105 Const. QED Let AB and EF be two parallel lines, and let HK be... | |
 | George Albert Wentworth - Geometry, Modern - 1899 - 272 pages
...parallel to a third straight l2ne are parallel to each other. PROPOSITION XI. THEOREM. 107. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also. n H? Let AB and EF be two parallel lines, and let HK be perpendicular to AB, and cut EF at C.... | |
 | George Albert Wentworth - Geometry, Solid - 1899 - 246 pages
...given point only one straight line can be drawn parallel to a given straight line. 107. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also. 114. When two straight lines in a plane are cut by a transversal, if the exterior-interior angles... | |
 | Arthur Schultze - 1901 - 260 pages
...parallel to AC, which is impossible. (Ax. 11.) Hence Z ABE =Z BEF. Q . E . D . 88. COR. If a transversal is perpendicular to one of two parallel lines, it is perpendicular to the other also. Ex. 58. If two parallels are cut by a transversal, the alternate exterior angles are equal. Ex.... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1902 - 394 pages
...would be parallel to AC, which is impossible. (Ax. 11.) Hence ZABE=ZBEF. QED 88. COR. If a transversal is perpendicular to one of two parallel lines, it is perpendicular to the other also. Ex. 58. If two parallels are cut by a transversal, the alternate exterior angles are equal. Ex.... | |
 | Arthur Schultze - 1901 - 392 pages
...would be parallel to AC, which is impossible. (Ax. 11.) Hence ZABE=ZBEF. QED 88. COR. If a transversal is perpendicular to one of two parallel lines, it is perpendicular to the other also. Ex. 58. If two parallels are cut by a transversal, the alternate exterior angles are equal. Ex.... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1901 - 396 pages
...be parallel to AC, which is impossible. (Ax. 11.) Hence Z ABE =Z BEF. QED 88. COR. If a transversal is perpendicular to one of two parallel lines, it is perpendicular to the other also. Ex. 58. If two parallels are cut by a transversal, the alternate exterior angles are equal. Ex.... | |
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If a line is perpendicular to one of two parallel lines, it is perpendicular to the other also. 
