 | Benjamin Greenleaf - 1862 - 518 σελίδες
...two right angles (Prop. I.) ; hence BGH, GHD are also equal to two right angles. 87. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other ; thus EF (Art. 85), perpendicular to AB, is perpendicular to CD. PROPOSITION XXIII. — THEOREM. 88.... | |
 | Benjamin Greenleaf - 1862 - 532 σελίδες
...two right angles (Prop. I.) ; hence BGH, GHD are also equal to two right angles. 87. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other ; thus EP (Art. 85), perpendicular to AB, is perpendicular to CD. PROPOSITION XXIII. — THEOREM. 88.... | |
 | Benjamin Greenleaf - 1863 - 504 σελίδες
...two right angles (Prop. I.) ; hence BGH, GHD are also equal to two right angles. 87. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other; thus EF (Art. 85), perpendicular to AB, is perpendicular to CD. PROPOSITION XXIII. — THEOREM. 88.... | |
 | Benjamin Greenleaf - 1868 - 340 σελίδες
...two right angles (Prop. I.); hence BGH, GHD are also equal to two right angles. 87. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other ; thus EF (Art. 85), perpendicular to AB, is perpendicular to CD. PROPOSITION XXIII. — THEOREM. "... | |
 | Benjamin Greenleaf - 1873 - 202 σελίδες
...two right angles (Theo. I.) ; hence BGH, GHD are also equal to two right angles. 65. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other. THEOREM XVIII. 66. If two angles have their sides parallel, each to each, and tying in the same direction,... | |
 | Benjamin Greenleaf - 1874 - 206 σελίδες
...two right angles (Theo. I.) ; hence BGH, GHD are also equal to two right angles. 65. Cor. If a line is perpendicular to one of two parallel lines, it is perpendicular to the other. THEOREM XVIII. 66. If two angles have their sides parallel, each to each, and lying in the same direction,... | |
 | George Albert Wentworth - 1877 - 416 σελίδες
...Alternateexterior angles. 2/3 1/4 6/7 5/8 GEOMETRY. — BOOK I. PROPOSITION X. THEOREM. 67. If a straight line be perpendicular to one of two parallel lines, it is perpendicular to the other. II •: С Let AB and EF be two parallel lines, and let HK be perpendicular to A B. We are to prove... | |
 | George Albert Wentworth - 1881 - 266 σελίδες
...and 8, 3 and 7 are called Exterior-interior angles. PROPOSITION X. THEOREM. 67. If a straight line be perpendicular to one of two parallel lines, it is perpendicular to the other. H M -._ -—-... С N К Let A В and EF be two parallel lines, and let HK be perpendicular to A B.... | |
 | George Albert Wentworth - 1888 - 264 σελίδες
...This method of proof is called the indirect method. PROPOSITION VII. THEOREM. 102. If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other. H: o -It E K Let AB and EF be two parallel lines, and let HK 63 perpendicular to AB. To prove HK±... | |
 | 1891 - 214 σελίδες
...because the majortiy use the science. The course of reasoning by which we prove, "If one straight line Is perpendicular to one of two parallel lines, it is perpendicular to the other," is not gone through with to ascertain tbe truth of a statement so evident, but to train the young mind... | |
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If a line is perpendicular to one of two parallel lines, it is perpendicular to the other also. 
