 Theorem. If each of two intersecting planes is perpendicular to a third plane, their line of intersection is also perpendicular to that plane. Given two planes, Q, R, intersecting in OP, and each perpendicular to plane M. To prove that OP _L M.  Solid Geometry - Page 268by Wooster Woodruff Beman, David Eugene Smith - 1900 - 139 pagesFull view - About this book
 | Henry Nathan Wheeler - Trigonometry - 1876 - 204 pages
...perpendicular to a line is perpendicular to every plane which contains the line. c. If two planes are each perpendicular to a third plane, their line of intersection is also perpendicular to the third plane. d. The measure of the angle between two planes is the angle between two straight lines... | |
 | Aaron Schuyler - Geometry - 1876 - 384 pages
...straight line, and is perpendicular to a given plane, is called the projecting plane of the line. 4. If each of two intersecting planes is perpendicular to a third plane, tlieir intersection is perpendicular to that plane. For, the perpendicular to the third plane, through... | |
 | Robert Fowler Leighton - 1877 - 372 pages
...parallelepiped ? How many edges ? How is the angle between two planes measured ? 2. Prove that if two planes are perpendicular to a third plane, their line of intersection is also perpendicular to the third plane. .. 3. Prove that the section of a pyramid made by a plane parallel to the base is... | |
 | Henry Nathan Wheeler - Plane trigonometry - 1878 - 198 pages
...perpendicular to a line is perpendicular to every plane which contains the line. c. If two planes are each perpendicular to a third plane, their line of intersection is also perpendicular to the third plane. d. The measure of the angle between two planes is the angle between two straight lines... | |
 | Edward Olney - Geometry - 1883 - 352 pages
...line upon a plane (468) is perpendicular to the plane of projection. Fig. 241. PROPOSITION III. 510. Theorem. — If each of two intersecting planes is perpendicular to a third, their intersection is perpendicular to the third plane. DEMONSTRATION. Let EF and CD be two planes... | |
 | E. J. Brooksmith - Mathematics - 1889 - 356 pages
...plane may be equally inclined to the plane. 2. If two planes which cut one another are each of them perpendicular to a third plane, their line of intersection is also perpendicular to the same plane. 3. Assuming that pyramids with equal bases and of equal altitudes are equal to one... | |
 | Wooster Woodruff Beman, David Eugene Smith - Geometry - 1895 - 346 pages
...would also include line OZ, else there would be two _L; from 0 to OX, in the plane MN. Theorem 19. If each of two intersecting planes is perpendicular...and each perpendicular to plane M. To prove that OP _L M. Proof. 1. A line from 0, _L M, lies in Q, also in R. Th. 18, cor. 1 2. .'.it coincides with OP,... | |
 | Wooster Woodruff Beman, David Eugene Smith - Geometry - 1895 - 344 pages
...plane would also include line OZ, else there would be two Jf from 0 to OX, in the plane MN. Theorem 19. If each of two intersecting planes is perpendicular...and each perpendicular to plane M. To prove that OP _L M. Proof. 1. A line from 0, _L M, lies in Q, also in R. Th. 18, cor. 1 SOLID GEOMETRY. Theorem 20.... | |
 | Henry W. Keigwin - Geometry - 1897 - 254 pages
...to one face of a right dihedral from any point in the other face, it lies in that other face. 415. THEOREM. If each of two intersecting planes is perpendicular to a third plane, their intersection is normal to the third plane. 416. THEOREM. A plane normal to the edge of a dihedral is... | |
 | Yale University - 1898 - 212 pages
...All lines perpendicular to another line at the same point lie in the same plane. 2. If each of two planes is perpendicular to a third plane, their line of intersection is also perpendicular to that third plane. 3. The sum of the angles of a spherical triangle is greater than two, and less than six,... | |
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