 | John Radford Young - Euclid's Elements - 1827 - 246 pages
...parallels makes (lie two interior angles on the same side together equal to two right angles. Cor. 5. A line perpendicular to one of two parallels is perpendicular to the other. Cor. 6. Therefore, if to each of two parallels perpendiculars be drawn, these perpendiculars shall... | |
 | Adrien Marie Legendre - Geometry - 1828 - 346 pages
...be parallel. 65. Cor. 1 . If GOC is a right angle, AGO will be a right angle also ; therefore every line perpendicular to one of two parallels is perpendicular to the other. 66. Cor. 2. Since the sum AGO+GOC is equal to two right angles, and the sum GOD+GOC is also equal to... | |
 | John Playfair - Euclid's Elements - 1835 - 336 pages
...two right angles. COR. 1. If BGH! is a right angle, GHD will be a right angle also ; therefore every line perpendicular to one of two parallels, is perpendicular to the other. COR. 2. Since AGE=BGH, and DHF=CHG; hence the four acute angles BGH, AGE, GHC, DHF, are equal to each... | |
 | Adrien Marie Legendre - Geometry - 1836 - 394 pages
...angles. Cor. I. If OGB is a right angle, GOD will be a right angle also: therefore, every straight line perpendicular to one of two parallels, is perpendicular to the other. Cor. 2. If a straight line meet two E/ parallel lines, the alternate angles will '/ be equal. ®L _... | |
 | John Playfair - Euclid's Elements - 1837 - 332 pages
...produced towards K and C. COR. 2. If BGH is a right angle, GHD will be a right angle also; therefore every line perpendicular to one of two parallels, is perpendicular to the other. C#R. 3. Since AGE=:BGH, and DHF = CHG ; hence the four acute angles BGH, AGE, GHC, DHF, are equal to... | |
 | Dionysius Lardner - Curves, Plane - 1840 - 386 pages
...- 27 CHAP. III. OF PARALLEL LINES. (28.) Difficulty of the Theory of Parallels - -29 * (31.) Every Line, perpendicular to one of two Parallels, is perpendicular to the other * - 31 (31.) Parallels are equidistant - - - 32 (37.) Systems of rectangular Parallels - - 33 Framing... | |
 | John Playfair - Euclid's Elements - 1842 - 332 pages
...towards K and C. COR. 2. If BGH is a right angle, GHD will be a right angle also ; therefore every line perpendicular to one of two parallels, is perpendicular to the other. COR. 3. Since AGE=BGH, and DHF=CHG; hence the four acute angles BGH, AGE, GHC, DHF, are equal to each... | |
 | Nathan Scholfield - 1845 - 894 pages
...angles. Cor. 1. If OGB is a right angle, GOD will be a right angle also ; therefore, every straight line perpendicular to one of two parallels, is perpendicular to the other. Cor. 2. If a right line meet two parallel lines, the alternate angles will be equal. Let AB, CD, (see... | |
 | Euclid, John Playfair - Euclid's Elements - 1846 - 334 pages
...towards K and C. COR. 2. If BGH is a right angle, GHD will be a right angle also ; therefore every line perpendicular to one of two parallels, is perpendicular to the other. COR. 3. Since AGE=BGH,and DHF=CHG ; hence the four acute angles BGH, AGE, GHC, DHF, are equal to each... | |
 | Charles Davies - Trigonometry - 1849 - 372 pages
...to two ]F Cor. 1. If OGB is a right angle, GOD will be a right angle also: therefore, every straight line perpendicular to one of two parallels, is perpendicular to the other. nght angles; then III and CD will be parallel (Prop. XIX.), and hence we shall have two lines GB, GH,... | |
| |
A line perpendicular to one of two parallels is perpendicular to the other also. 
