 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.  A Text-book of Geometry - Page 270by George Albert Wentworth - 1894 - 437 pagesFull view - About this book
 | Sir Norman Lockyer - Electronic journals - 1902 - 1074 pages
...angles between a line which meets a plane and the lines in the plane than Prop. xx. in § 449, viz., " The acute angle which a straight line makes with its own projection upon a plane is the least angle it makes with any line of that plane." It is advantageous to know, not only the least and the greatest... | |
 | Sir Norman Lockyer - Electronic journals - 1902 - 688 pages
...angles between a line which meets a plane and the lines in the plane than Prop. xx. in § 449, viz., " The acute angle which a straight line makes with its own projection upon a plane is the least angle it makes with any line ofthat plane." It is advantageous to know, not only the least and the greatest... | |
 | William Chauvenet - Geometry - 1871 - 380 pages
...the straight line AB upon the plane MN. \ PROPOSITION XXIII.— THEOREM. 59. The acute angle ichich a straight line makes with its own projection upon...is the least angle which it makes with any line of that plane. Let Ba be the projection of the straight line BA upon the plane MN, the point B being the... | |
 | William Chauvenet - Geometry - 1871 - 380 pages
...any oblique line; therefore, the angle ABa is less than the angle ABC (I. 85). ~F*~ 60. Definition. The acute angle which a straight line makes with its own projection upon a plane is called the inclination of the line to the plane, or the angle of the line and plane. 61. Definition.... | |
 | William Chauvenet - Mathematics - 1872 - 382 pages
...than any oblique line ; therefore, the angle ABa is less than the angle ABC (I. 85). 60. Definition. The acute angle which a straight line makes with its own projection upon a plane is called the inclination of the line to the plane, or the angle of the line and plane. 61. Definition.... | |
 | Aaron Schuyler - Geometry - 1876 - 384 pages
...which are equally distant from two given points. 3. The angle which a straight line makes with its projection upon a plane is the least angle which it makes with any line of that plane. 5. Find the locus of the points which are equally distant from two given straight lines... | |
 | George Albert Wentworth - Geometry - 1877 - 416 pages
...PROPOSITION XXI. THEOREM. 478. The aciife angle which a straight line makes with its own projection on a plane is the least angle which it makes with any line of that plane. A Let BA meet the plane MN at В, and let B A' be its projection upon the plane M У, and... | |
 | George Albert Wentworth - Geometry - 1877 - 426 pages
...homologous sides of equal A ). QED SOLID ANGLES. SUPPLEMENTARY PROPOSITIONS. PROPOSITION XXI. THEOREM. 478. The acute angle which a straight line makes with its own projection on a plane is the least angle winch it makes with any line of that plane. Let BA meet the plane MN... | |
 | Isaac Sharpless - Geometry - 1879 - 282 pages
...are at right angles to each other. 6. The acute angle which a line makes with its own projection on a plane, is the least angle which it makes with any line on the plane. See Def. of projection, and use the last Ex. and (I. 23). 7. If a plane be passed through... | |
 | William Chauvenet - Geometry - 1887 - 342 pages
...PROPOSITION XVIII. The projection of a straight line upon a plane is a straight line. PROPOSITION XIX. The acute angle which a straight line makes with its own projection upon a plane is the least angle it makes with any line of that plane. PROPOSITION XX. The sum of any two face angles of a triedral... | |
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