 | Euclides - 1841 - Страниц: 378
...in that plane. Wherefore, if two straight lines, &c. QED PROP. VIII. THEOR. If two straight lines be parallel, and one of them is at right angles to a plane; the other also shall be at right angles to the same plane. Let AB, CD be two parallel straight lines, and let... | |
 | John Playfair - 1842 - Страниц: 332
...is parallel (Cor. 28. 1.)toCD. PROP. VII. THEOR. If two straight lines be parallel, and one of them at right angles to a plane ; the other is also at right angles to the same plane. Let AB, CD be two parallel straight lines, and let one of them AB be at -A. C right angles to a plane... | |
 | Euclides - 1842 - Страниц: 316
...if two straight lines, !. QED PEOP. VII. THEOR. IF two straight lines be parallel, and one of them at right angles to a plane : the other is also at right angles to the same plane. Let AB, CD be two parallel straight lines, and let one of them, AB be perpendicular to a plane: the... | |
 | Euclides - 1845 - Страниц: 546
...plane. Wherefore, if two straight lines, &c. QED PROPOSITION VIII. THEOREM. If two straight lines be parallel, and one of them is at right angles to a plane ; the other also shall be at right angles to the same plane. Let AB, CD be two parallel straight lines, and let... | |
 | Euclid - 1845 - Страниц: 218
...plane. Wherefore, if two straight lines, &c. QED PROPOSITION VIII. THEOR. — If two straight lines be parallel, and one of them is at right angles to a plane, tlte other also shall be at right angles to the same plane. Let AB, CD be two parallel straight lines,... | |
 | Dennis M'Curdy - 1846 - Страниц: 168
...of b. 1; p. 2 and 5 of this; p. 28 of b. 1. 7 Th. If two straight lines be parallel, and one of them at right angles to a plane; the other is also at right angles to the same plane. Recite p. 6 of this; ax. 11 of b. 1. 8 Th. Two straight lines, which are, each of them, parallel to... | |
 | Euclid, John Playfair - 1846 - Страниц: 334
...is parallel (Cor. 28. 1.)toCD. PROP. VII. THEOR. If two straight lines be parallel, and one of them at right angles to a plane ; the other is also at right angles to the same plane. Let AB, CD be two parallel straight lines, and let one of them AB be at -Aright angles to a plane ;... | |
 | Euclides - 1848 - Страниц: 52
...in the other, is in the same plane with the parallels. PROP. VIII. THEOREM. If two straight lines be parallel, and one of them is at right angles to a plane ; the other also shall be at right angles to the same plane. PROP. IX. THEOREM. Two straight lines which are each... | |
 | Robert Potts - 1855 - Страниц: 1050
...and the other cutting it in C and D, the triangles ABC, ABD are similar. 7. If two straight lines be parallel, and one of them is at right angles to a plane ; the other also shall be at right angles to the same plane. 8. Prove that in the parabola, SY is a mean proportional... | |
 | Euclides - 1855 - Страниц: 270
...plane of ED and D A. Bat GH is parallel to B С ; and if two straight lines be parallel, one of which is at right angles to a plane, the other is also at right (XI. 8) angles to the plane. Therefore GH is at right angles to the plane of ED and DA ; and is perpendicular... | |
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be parallel, and one of them, at right angles to a plane ; the other is also at right angles to the same plane. Let AB... 
