 | Isaac Newton Failor - Geometry - 1906 - 431 pages
...the plane. 294 PROPOSITION XXIII. THEOREM 577 The acute angle which a straight line makes with its projection upon a plane is the least angle which it makes with any line in the plane. HYPOTHESIS. BC is the projection of AB upon the plane MN, and BD is any other line in MN.... | |
 | Isaac Newton Failor - Geometry - 1906 - 440 pages
...GEOMETRY -BOOK VI PROPOSITION XXIII. THEOREM 577 The acute angle which a straight line makes with its projection upon a plane is the least angle which it makes with any line in the plane. HYPOTHESIS. BC is the projection of AB upon the plane MN, and BD is any other line in MN.... | |
 | Edward Rutledge Robbins - Geometry - 1907 - 428 pages
...Proof : By reditctio ad absurdum. (See 88, 89). SOLID GEOMETRY 521. THEOREM. The acute angle that a line makes with its own projection upon a plane is the least angle that the line makes with any line of the plane. Given : AB, any line meeting plane MN at B ; BP, its... | |
 | Webster Wells - Geometry - 1908 - 336 pages
...angles are equal. PROP. XXIX. THEOREM 398. The angle between a straight line and its projection on a plane is the least angle which it makes with any line drawn in the plane through its foot. JfGiven line BC the projection of line AB on plane MN, and BD... | |
 | Herbert Ellsworth Slaught, Nels Johann Lennes - Geometry, Solid - 1911 - 208 pages
...the given plane. , 59. THEOREM. The acute angle formed by a straight line with its own projection on a plane is the least angle which it makes with any line in that plane. Outline of Proof : Let BC be the projection of AB, and let BD be any other line in M through B. Lay... | |
 | Clara Avis Hart, Daniel D. Feldman, Virgil Snyder - Geometry, Solid - 1912 - 216 pages
...line and its projection upon a plane always lie in the same plane. Ex. 1186. (a) The acute angle that a straight line makes with its own projection upon a plane is the least angle that it makes with any line passing through its foot in the plane. (6) With what line passing through... | |
 | Clara Avis Hart, Daniel D. Feldman - Geometry - 1912 - 504 pages
...and its projection upon a plane always lie in the same plane. Ex. 1186. (a) The acute angle that • straight line makes with its own projection upon a plane is the least angle ^ that it makes with any line passing through its foot in the plane. (6) With what line passing through... | |
 | William Herschel Bruce, Claude Carr Cody - Geometry, Solid - 1912 - 134 pages
...projecting plane. PROPOSITION XIX. THEOREM. 581. The acute angle which a line makes with its projection on a plane is the least angle which it makes with any line of that plane. Given BC the projection of the line AB on the plane MN, and BD any other line, drawn... | |
 | George Albert Wentworth, David Eugene Smith - Geometry - 1913 - 496 pages
...the line to the plane. PROPOSITION XXIII. THEOREM A 486. The acute angle which a line makes with its projection upon a plane is the least angle which it makes with any line of the plane. N Given the line AB meeting the plane MN&t A, Aff being the projection of AB upon the... | |
| |
The acute angle which a straight line makes with its projection upon a plane is the least angle which it makes with any line of the plane. 
