 If a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also.  Plane Geometry - Page 43by Claude Irwin Palmer, Daniel Pomeroy Taylor - 1915 - 277 pagesFull view - About this book
 | Elias Loomis - Conic sections - 1849 - 252 pages
...therefore, also, BGH, GHD are equal to two right angles. Therefore, if a straight line, &c Cor. 1. If a straight line is perpendicular to one of two parallel lines, it is also perpendicular to the other. For if they do not meet, they are parallel (Def. 12). But they are... | |
 | Elias Loomis - Conic sections - 1858 - 256 pages
...therefore, also, BGH. GHD are equal to two right an gles. Therefore, if a straight line, &c Cor. 1. If a straight line is perpendicular to one of two parallel lines, it is also perpendicular to the other. Cor. 2. If two lines, KL and CD, make with EF the two angles KGH,... | |
 | Benjamin Greenleaf - Geometry - 1861 - 638 pages
...equal to 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 C D. PBOPOSITION XX11I. — THEOREM.... | |
 | Benjamin Greenleaf - Geometry - 1862 - 518 pages
...equal to 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 - Geometry - 1863 - 504 pages
...equal to 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 - Geometry - 1868 - 340 pages
...equal to 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. "... | |
 | Elias Loomis - Geometry - 1871 - 302 pages
...therefore, also, BGH. GHD are equal to two right an gles. Therefore, if a straight line, &c Cor. 1. If a straight line is perpendicular to one of two parallel lines, it is also perpendicular to the other. Cor. 2. If two lines, KL and CD, make with EF the two angles KGH,... | |
 | Benjamin Greenleaf - Geometry - 1873 - 202 pages
...equal to 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 - Geometry - 1874 - 206 pages
...equal to 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 - Geometry - 1877 - 416 pages
...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... | |
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