 | Robert Simson - Trigonometry - 1762 - 488 pages
...hath length, breadth, and thicknefs. II. That which bounds a folid is a fuperficies. III. A ftraight line is perpendicular, or at right angles, to a plane, when it makes right angles with every ftraight line meeting it in that plane. rv. A plane is perpendicular to a plane, when the ftraight... | |
 | Robert Simson - Trigonometry - 1775 - 534 pages
...hath length, breadth, and thickneft. II. That which bounds a fblid is a fuperficies. 111. A ftraight line is perpendicular, or at right angles to a plane, when it makes right angles with every ftraight line meeting it in that plane. IV. A plane is perpendicular to a plane, when the ftraight... | |
 | Euclid - 1781 - 552 pages
...which hath length, breadth, and thicknefs, That which bounds a folid is a uoerficies. Ill A ftraight line is perpendicular, or at right angles to a plane, when it makes right angles with every itraight line meeting it in that plane. IV. A plane is perpendicular to a plane, when the ftraight... | |
 | Euclid, John Playfair - Euclid's Elements - 1795 - 462 pages
...it makes right angles with every ftraight line which meets it in that plane. But a ftraight line is at right angles to a plane when it makes right angles with every ftraight line which meets it in that.plane f : therefore EK is at right an.-V f i.3 to the plane in... | |
 | Alexander Ingram - Trigonometry - 1799 - 374 pages
...hath length, breadth, and thicknefs. >^ n. That which bounds a folid is a fuperficies. III. A ftraight line is perpendicular, or at right angles to a plane, •when it makes right angles with every ftraight line meeting it in that plane. IV. A plane is perpendicular to a plane, when the ftraight... | |
 | John Playfair, Euclid - Circle-squaring - 1804 - 468 pages
...ELEMENTS oF GEOMETRY. SUPPLEMENT, • BOOK II. OF THE INTERSECTIoN oF PLANES. I 4 .DEFINITIONS. I. A STRAIGHT line is perpendicular, or at right angles...to a plane, when it makes right angles with every ftraight * line, in that plane, which it meets. II. A plane is perpendicular to a plane, when the ftraight... | |
 | Robert Simson - Trigonometry - 1804 - 530 pages
...hath length, breadth, and thicknefs. II. That which bounds a folid is a fupcrficies. III. A ftraight line is perpendicular, or at right angles, to a plane, when it makes right angles with every ftraight line meeting it in that plane. IV. A plane is perpendicular to a plane, when the ftraight... | |
 | Robert Simson - Trigonometry - 1806 - 546 pages
...FE makes right angles with every straight line which meets it in that plane. But a straight line is at right angles to a plane when it makes right angles with every straight line which meets it in that plane f : therefore EF is at right an- f 3. def. gles to the plane in which... | |
 | John Playfair - Mathematics - 1806 - 320 pages
...lines BD, BE, it is also at right angles'1 b*. 2. Sup. to the plane passing through them, and therefore makes right angles with every straight line meeting it in that plane. But BF meets AB in that plane ; therefore the angle ABF is a right angle. But, by the Viypothesis,... | |
 | John Mason Good - 1813 - 714 pages
...that wh.ich hath length, breadth, and thickness. 2. That which bounds a solid is a superficies. 3. A straight line is perpendicular, or at right angles...with every straight line meeting it in that plane. 4. A plane is perpendicular to a plane, »hen the straight lines drawn in one of the planes perpendicularly... | |
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A plane is perpendicular to a plane, when the straight lines drawn in one of the planes perpendicular to the common section of the two planes, are perpendicular to the other plane. 5. The inclination of a straight line to a plane... 
