 | Peter Nicholson - Mathematics - 1825 - 1046 pages
...if perpendicular to each of the straight lines GH, DE. But if a straight line stands at right anglei to each of two straight lines in the point of their...intersection, it shall also be at right angles to the plane passing through them. But the plane passing through ED, GH, is the plane BH ; therefore AF is perpendicular... | |
 | Robert Simson - Trigonometry - 1827 - 546 pages
...AF is perpendicular to DE; therefore AF is perpendicular to each of the straight lines GH, DE. But if a straight line stand at right angles to each of two straight lines in the point t 4. 11. of their intersection, it is also at right angles -)- to the plane passing through them :... | |
 | Pierce Morton - Geometry - 1830 - 584 pages
...and perpendicular itraight line. A straight line when said to be perpendicular to a plane . . 125 (a) If a straight line stand at right angles to each of two otlter straight lines at their point of intersection, it shall be at right angles to the plane in which... | |
 | John Playfair - Euclid's Elements - 1832 - 358 pages
...BC, or it is the common section of these planes. QED 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 are. Let the straight line AB stand... | |
 | John Playfair - Euclid's Elements - 1833 - 346 pages
...: Therefore AF is perpendicular toeach of the straight lines GH, DE. But if a straight line stands at right angles to each of two straight lines in the point of their inter. section, it is also at right angles to the plane passing through them (4. 2. Sup.). And the... | |
 | Euclides - 1834 - 518 pages
...AF is perpendicular to DE ; therefore AF is perpendicular to each of the straight lines GH, DE. But if a straight line stand at right angles to each of...straight lines in the point of their intersection, it is also at right angles t to the plane passing through f 4. 1 1. them : but the plane passing through... | |
 | Euclid - 1835 - 540 pages
...BC, cannot but be a straight line. Wherefore, " if two planes" &c. QED L. 'A PROP. IV. THEOR. See N. If a straight line stand at right angles to each of...straight lines in the point of their intersection, if shall also be at right angles to the plane which passes through them, that is, to the plane in which... | |
 | Robert Simson - Trigonometry - 1835 - 544 pages
...: Therefore AF is perpendicular to each of the straight lines GH, DE. But if a straight line stands at right angles to each of two straight lines in the point of their intersection, it is also at right angles to the plane passing through them*. But the plane passing through ED, GH, is... | |
 | Mathematics - 1835 - 684 pages
...and perpendicular straight line. A straight line when said to be perpendicular to a plane , . 125 (a) If a straight line stand at right angles to each of two other straight lines at their point of intersection, it shall be at right angles to the plane in which... | |
 | John Playfair - Euclid's Elements - 1836 - 488 pages
...planes AB and BC, or it is the common section of these planes. Therefore, &c. QE D, PROP. IV. THEOR. If a straight line stand at right angles to each of two straight lines in the point of their in~ terscction, it will also be at right angles to the plane in which these lines are. Let the straight... | |
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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. 
