 | Euclides, James Thomson - Geometry - 1845 - 382 pages
...cannot but be a straight line.* Therefore, &c. Puor. IV. THEOR. — If a straight line be perpendicular to each of two straight lines at their point of intersection, it is also perpendicular to the plane in which they are. Let the straight lineEF be perpendicular to each... | |
 | Scottish school-book assoc - 1845 - 444 pages
...common section of the two planes is a straight line. GEOMETRY OF PLANES. PBOPOSITION LXXX — THEOREM. If a straight line stand at right angles to each of two traight lines in the point of their intersection, it will also e at right angles to the plane in which... | |
 | John Playfair - Euclid's Elements - 1846 - 332 pages
...therefore common to the planes AB and BC, or it is the common sectioa of these planes. PROP. IV. THEOR. If a straight line stand at right angles to each of two straight lines in the point of their intersection, it will also be at right angles to the plane in which these lines... | |
 | Euclides - 1846 - 292 pages
...planes AB, BC, cannot but be a straight line. Wherefore, If two planes %c. ct. KD PROP. IV. THEOR. If a straight line stand at right angles to each of two straight lines in the point of their intersection, it shall also be at right angles to the plane which passes through... | |
 | 1846 - 536 pages
...too, by Euclid with an elegance fully equal to that by which any other author has proved it,) that "if a straight line stand at right angles to each of two stright lines at their point of intersection, it shall also be at right angles to every other line... | |
 | Perry Fairfax Nursey - Industrial arts - 1846 - 536 pages
...too, by Euclid with an elegance fully equal to that by which any other author has proved it,) that "if a straight line stand at right angles to each of two stright lines at their point of intersection, it shall also be at right angles to every other line... | |
 | Samuel Hunter Christie - 1847 - 172 pages
...section of the planes AB, BC, cannot but be a straight line: which was to be proved. PROP. IV. THEOR. If a straight line stand at right angles to each of two straight lines in the point of their intersection, it shall also be at right angles to the plane which passes through... | |
 | John Playfair - Euclid's Elements - 1849 - 332 pages
...therefore common to the planes AB and BC, or it is the common section of these planes. PROP. IV. THEOR. If a straight line stand at right angles to each of two straight hnes in the point of their intersection, it will also be at right angles to the plane in which these... | |
 | Elias Loomis - Conic sections - 1849 - 252 pages
...common section. Hence, if two planes, &c. PROPOSITION IV. THEOREM. If a straight line be perpendicular to each of two straight lines at their point of intersection, it will be perpendicular to the plane in which these lines are. Through B draw any line BG, in the plane MN;... | |
 | Royal Military Academy, Woolwich - Mathematics - 1853 - 400 pages
...angle, the planes are said to be perpendicular to one another. 5. If a straight line be perpendicular to each of two straight lines at their point of intersection, it is said to be perpendicular to the plane passing through those two lines. Conversely, the plane is... | |
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If a straight line stand at right angles to each of two straight lines at the point of their intersection, it shall also be at right angles to the plane which passes through them, that is, to the plane in which they are. 
