Books Books DEFINITIONS. 1 . A straight line is perpendicular to a plane, when it is perpendicular to every straight line of the plane which it meets. An Elementary Geometry - Page 64
by William Frothingham Bradbury - 1872 - 110 pages ## Elements of Geometry: Containing the Principal Propositions in the First Six ...

Euclid - Euclid's Elements - 1789 - 296 pages
...1. The common fection of two planes, is the line in which they meet, or cut each other. 2. A right line is perpendicular to a plane, when it is perpendicular to every right line which meets it in that plane. 3. A plane is perpendicular to a plane, when every right line... ## A Course of Mathematics: For the Use of Academies as Well as Private Tuition

Charles Hutton - Mathematics - 1812 - 620 pages
...DEF. 88. The Common Section of two Planes, is the line in which they meet, to cut each other. 89. A Line is Perpendicular to a Plane, when it is perpendicular to every line in that plane which meets it. 90. One Plane is Perpendicular to Another, when every line of the... ## A Philosophical and Mathematical Dictionary: Containing an ..., Volume 2

Charles Hutton - Astronomy - 1815 - 686 pages
...perpendicular to a curve, when it is perpendicular to the tanpent of the curve at the point of con- =, tact. A line is perpendicular to a plane, when it is perpendicular to every line drawn in the plane through the bottom of the perpendicular. And one plane is perpendicular to... ## Encyclopaedia Perthensis; Or Universal Dictionary of the Arts ..., Volume 10

Encyclopedias and dictionaries - 1816 - 764 pages
...THE COMMON SECTION of two planes, is the line in which tht-r meet, or cut each other. 68. A ftraight line is PERPENDICULAR, to. a plane, when it is perpendicular to every line which meets it in that plane. 69. One plane is PERPENDICULAR to another, vhen every right line... ## Elements of Geometry

Adrien Marie Legendre - Geometry - 1819 - 574 pages
...FIRST. '• ' . : .'•!. ..',•. - : V. -. '-.I Of planes and solid angles. .... . . 313. A 8TRAIGHT line is perpendicular to a plane, when it is perpendicular to every straight line in the plane which passes through the foot of the perpendicular (326). Reciprocally, the plane, in... ## Elementary Illustrations of the Celestial Mechanics of Laplace: Part the ...

Pierre Simon marquis de Laplace, Thomas Young - Capillarity - 1821 - 388 pages
...and, the radius being unity, 1°=:.01 7453293, 1'=.000290888, and 1"=: .000004848. 145. DEFINITION. A straight line is perpendicular to a plane, when it is perpendicular to every straight line meeting it in that plane. 146. DEFINITION. A plane is perpendicular to a plane, when all the straight... ## Elements of Geometry and Trigonometry: With Notes

Adrien Marie Legendre - Geometry - 1822 - 394 pages
...circle is greater than any isoperi metrical polygon. BOOK V. PLANKS AND SOLID ANGLES. Definitions. I. A straight line is perpendicular to a plane, when it is perpendicular to all the straight lines (4. IV.) which pass through its foot in the plane. Conversely, the plane is... ## A Course of Mathematics: For the Use of Academies, as Well as Private ...

Charles Hutton - Mathematics - 1822 - 616 pages
...DEF. 88. The common Section of two Planes, is the line m which they meet, to cut each other. 89. A line is Perpendicular to a Plane, when it is perpendicular to every line in that plane which meets it. 90. One Plane is Perpendicular to Another, when every line of the... ## A treatise on navigation, and nautical astronomy

Edward Riddle - Nautical astronomy - 1824 - 572 pages
...therefore AD . BD + В E . E С = AF . FG + AF . GC, or = AF . F C. ON THE INTERSECTION OF PLANES. DEFINITIONS. 1. A STRAIGHT line is perpendicular to a plane when it makes right angles with every straight line which it meets in that plane. 2. Two planes are perpendicular... 