 | George Roberts Perkins - 1860 - 472 σελίδες
...intersection of the two planes is in a straight line. THEOREM IV. If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of these lines. Let AP be perpendicular to the two* lines PB, PC, at... | |
 | Benjamin Greenleaf - 1862 - 518 σελίδες
...planes AB, CD is a straight line. PROPOSITION IV. — THEOREM. 401. If a straight line is perpendicular to each of two straight lines, at their point of intersection, it is perpendicular to the plane in which the two lines lie. Let the straight line AB be perpendicular... | |
 | Benjamin Greenleaf - 1862 - 532 σελίδες
...planes AB, CD is a straight line. PROPOSITION IV. — THEOREM. 401. If a straight line is perpendicular to each of two straight lines, at their point of intersection, it is perpendicular to the plane in which the two lines lie. Let the straight line AB be perpendicular... | |
 | Benjamin Greenleaf - 1863 - 504 σελίδες
...AB, CD is a straight line. B 1> PROPOSITION IV. — THEOREM. 401. If a straight line is pcrpemlicular to each of two straight lines, at their point of intersection, it is perpendicular to the plane in which the two lines lie. Let the straight line AB be perpendicular... | |
 | Euclides - 1864 - 448 σελίδες
...and AFis perpendicular to DE; therefore AFis 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 :... | |
 | Euclides - 1865 - 402 σελίδες
...plane can he drawn through three points which are not on the same right line * . . . . . XI. 2. 3. 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 through them, that is,... | |
 | Robert Potts - 1865 - 528 σελίδες
...and AFis perpendicular to DE; therefore AFis 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 :... | |
 | James Robert Christie - 1866 - 428 σελίδες
...internally, any straight line drawn through the point of contact will cut off similar segments. 4. If a straight line stand at right angles to each of...straight lines at their point of intersection, it shall also be at right angles to the plane which passes through them, that is, to the plane in which... | |
 | Euclid, Isaac Todhunter - 1867 - 426 σελίδες
...planes AB and EC cannot but be a straight line. Wherefore, if two planes &c. QED PROPOSITION 4. THEOREM. If a straight line stand at right angles to each of two straight lines at the -point of their intersection, it shall also lie at right angles to the plane which passes through... | |
 | Euclid, Isaac Todhunter - 1867 - 424 σελίδες
...AB and BC cannot but be a straight line. Wherefore, if t wo planes &c. QED PROPOSITION 4. THEOREM. 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... | |
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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. 
