| Edward Brooks - Geometry - 1868 - 275 pages
...to their intersection is perpendicular to the other. 4. If two planes which cut each other are both **perpendicular to a third plane, their intersection is perpendicular to that plane.** 6. Prove that through a line parallel to a given plane, only one plane perpendicular to the given plane... | |
| William Chauvenet - Geometry - 1871 - 368 pages
...number of planes can be passed through it perpendicular to MN(47). PROPOSITION XX.— THEOREM. 53. **If two intersecting planes are each perpendicular to a third plane, their intersection is** also perpendicular to that plane. Let the planes PQ, US, intersecting in the line AB, be perpendicular... | |
| William Chauvenet - Geometry - 1872 - 368 pages
...number of planes can be passed through it perpendicular to MN (47). PROPOSITION XX.— THEOREM. 53. **If two intersecting planes are each perpendicular to a third plane, their intersection is** also perpendicular to tliat plane. Let the planes PQ, US, intersecting in the line AB, be perpendicular... | |
| William Guy Peck - Conic sections - 1876 - 366 pages
...other at a common point, each is perpendicular to the plane of the other two. Cor. 3. If two planes are **perpendicular to a third plane, their intersection is perpendicular to that plane.** PROPOSITION XV. THEOREM. BOOK VI. Let AOC, COD, and DOA be the lateral angles of the triedral angle... | |
| Evan Wilhelm Evans - Geometry - 1884 - 149 pages
...How can you draw a line upon the wall, which will be perpendicular to the floor? THEOREM IX. If two **planes are each perpendicular to a third plane, their intersection is perpendicular to that plane.** The perpendicular to the plane HO, at the point C, must lie in both the planes, MN and SD(?). Hence,... | |
| W. E. BYERLY - 1887
...from any point of one plane perpendicular to the other will lie in the first plane. PROPOSITION XVI. **If two intersecting planes are each perpendicular to a third plane, their intersection is** also perpendicular to that plane. PROPOSITION XVII. Through any given straight line a plane can be... | |
| William Chauvenet - Geometry - 1887 - 322 pages
...to the other will lie in the first plane, (v. Proposition III.) PROPOSITION XVI.— THEOREM. 39. Jf **two intersecting planes are each perpendicular to a third plane, their intersection is** also perpendicular to that plane. Let the planes PQ, ES, intersecting in the lino ^17?. be perpendicular... | |
| Edward Albert Bowser - Geometry - 1890 - 393 pages
...planes, which is a straight line. (495) BOOK VI.— PERPENDICULAR PLANES. Proposition 1 8. Theorem. 546. **If two intersecting planes are each perpendicular...third plane, their intersection is perpendicular to** the third plane. Hyp. Let the planes PQ, RS, intersecting in AB, be J_ to the third plane MN. To prove... | |
| Seth Thayer Stewart - Geometry, Plane - 1891 - 406 pages
...planes, perpendicular to a third plane, it follows, in general, that : If two intersecting planes are **perpendicular to a third plane, their intersection is perpendicular to that plane.** PROPOSITION XIII. 447. Theorem : The sum of any two of the three plane angles formed by the edges of... | |
| George Albert Wentworth - Geometry - 1892 - 437 pages
...Z. CDE is a right angle, and therefore PAB is _L to MN § 514 QED PROPOSITION XIX. THEOREM. 520. I/ **two intersecting planes are each perpendicular to a third plane, their intersection is** also perpendicular to that plane. 7 J o Let the planes BD and BC intersecting in the line AB be perpendicular... | |
| |