| William Guy Peck - Conic sections - 1876 - 376 pages
...formed by drawing lines through any point respectively parallel to the given lines. PROPOSITION VI. THEOREM. If one of two parallel lines is perpendicular to a plane, the other one is also perpendicular to that plane. Let PQ and RS be parallel, and let PQ be perpendicular to... | |
| William Henry Harrison Phillips - Geometry - 1878 - 236 pages
...The centre of the circumference drawn through these points will be the foot of the perpendicular. IV. Theorem. If one of two parallel lines is perpendicular to a plane, the other is perpendicular to the same plane. HYPOTII. AB || CD, and AB _L MN. To BE PROVED. CD_LMN. PROOF. Through... | |
| George Shoobridge Carr - Mathematics - 1880
...in the same plane. XI. 6. — Right lines perpendicular to the same plane are parallel. XI. 8. — If one of two parallel lines is perpendicular to a plane, the other is also. XI. 20. — Any two of three plane angles containing a solid angle are greater than the third.... | |
| George Shoobridge Carr - Mathematics - 1886 - 1036 pages
...in the same plane. XI. 6. — Bight lines perpendicular to the same plane are parallel. XI. 8. — If one of two parallel lines is perpendicular to a plane, the other is also. XI. 20. — Any two of three plane angles containing a solid angle are greater than the third.... | |
| William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...parallel and lying in the same direction, they are equal and their planes are parallel. PROPOSITION XI. If one of two parallel lines is perpendicular to a plane, the other is also perpendicular to that plane. Corollary. Two straight lines perpendicular to the same plane... | |
| William Chauvenet - Geometry - 1888 - 826 pages
...therefore the plane MN of these lines is parallel to the plane M'N' (31). PBOPOSITIOX XIV.— TIIEOREM. 33. If one of two parallel lines is perpendicular to a plane, the oilier is also perpendicular to that plane. Let AB, A'B', be parallel lines, and let AB be perpendicular... | |
| Edward Albert Bowser - Geometry - 1890 - 420 pages
...CD lie in the same plane, and they are both J_ to BD. (487) .-. ABis || to CD. (70) QED 510. COR. 1. If one of two parallel lines is perpendicular to a plane, the other is also perpendicular to that plane. AC For, if AB is || to CD, and J_ to the plane MN, then a X to... | |
| William C. Bartol - Geometry, Solid - 1893 - 112 pages
...plane which has been passed through A, parallel to PQ; ie, MN is parallel toPQ. PROPOSITION VII. 23. THEOREM. If one of two parallel lines is perpendicular to a plane, the other is also perpendicular to the plane. E D Let the line BA be perpendicular to the plane xy; and let the... | |
| William Chauvenet - 1893 - 340 pages
...parallel and lying in the same direction, they are equal and their planes are parallel. PROPOSITION XI. If one of two parallel lines is perpendicular to a plane, the other is also perpendicular to that plane. Corollary. Two straight lines perpendicular to the same plane... | |
| Wooster Woodruff Beman, David Eugene Smith - Geometry - 1895 - 346 pages
...OC2 + OA2 - 2 . PO2 + 2 . OB2 + 2 - BC2 ; .'. PB2 = PO- + OB-> ; .'. /_ POB is a rt. ^/. Theorem 9. If one of two parallel lines is perpendicular to a plane the other is also. Given OY II O'Y', OY J_ plane MN at 0, and O'Y' meeting plane MN at 0'. To prove that O'Y'... | |
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