 | 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 Martin Frederick Wright - Mathematics - 1836 - 776 pages
...perpendiculars from the angular points. EUCLID, BOOK XI. 1817. 1 . DEFINE the five regular solid figures. 2. 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... | |
 | Mathematics - 1836 - 488 pages
...are in one plane. III. If two planes cut one another, their common section is a straight line. IV. If a straight line stand at right angles to each of two straight lines in their point of intersection, it will also be at right angles to the plane in which these lines are.... | |
 | A. Bell - Conic sections - 1837 - 180 pages
...common to the planes AB and BC, or it is the common section of these planes. PROPOSITION IV. THEOREM. 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... | |
 | Euclid, James Thomson - Geometry - 1837 - 410 pages
...straight line.* Therefore, if two planes, &c. PROP. 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 line EF be perpendicular to... | |
 | Euclides - Geometry - 1841 - 378 pages
...the planes AB, BC cannot but be a straight line. Wherefore, if two planes, &c. 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 shall also be at right angles to the plane which passes through... | |
 | John Playfair - Euclid's Elements - 1842 - 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 lines in the point of their intersection, it will also be at right angles to the plane in which these lines... | |
 | Euclides - 1842 - 316 pages
...planes AB and BC, or it is the common section of these planes. Therefore, &c. 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... | |
 | Euclides - 1845 - 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 of their intersection, it is also at right angles to the plane passing through them :... | |
 | Euclid - Geometry - 1845 - 218 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 of their intersection, it shall * 4. 11. also be at right angles* to the plane passing... | |
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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. 
