| Robert Simson - Trigonometry - 1806 - 546 pages
...planes AB, BC cannot but be a straight line. Wherefore, if two planes, &c. QED PROP. IV. THEOR. SeeN. 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 ri^ht angles to the plane which... | |
| John Playfair - Mathematics - 1806 - 320 pages
...is the common section of these planes. Therefore, if two planes, &c. QED A PROP. IV. THEOR. a 2. 6. 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... | |
| John Mason Good - 1813 - 714 pages
...III. Theor. If two planes cut one another, their common section is a straight line. Piop. 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... | |
| John Playfair - Circle-squaring - 1819 - 350 pages
...planes AB and BC, or it is the common section of these planes. Therefore, &c. Q,. ED 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... | |
| Mathematics - 1821 - 464 pages
...yards cost £2%, find the value of 5-f yards lx>th by vulgar fractions and by decimals. 2. Prove that if a straight line stand at right angles to each of two straight lines in the point of their intersection, it will be at right angles to the plane that passes... | |
| Peter Nicholson - Mathematics - 1825 - 1046 pages
...section of the planes AB, RC cannot but be a straight line. Wherefore, if two planes, &c. QED PROP. IV. THEOREM. If a straight line stand at right angles to each of tnio straight lines in the point of their intersection, it shall alto be ai right angles to the plane... | |
| Robert Simson - Trigonometry - 1827 - 546 pages
...AB, BC, cannot but be a straight line. Wherefore, if two planes, &c. Q. E, D. PROP. IV. THEOR. See N. 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... | |
| 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... | |
| Mathematics - 1835 - 684 pages
...joins any two of its points, that is, it is a straight line. Therefore, &c. PROP. 3. (Еве. xi. 4.) If a straight line stand at right angles to each of two other straight lines at their point uf intersection, it shall be at right angles to every other straight line which pauses through the... | |
| 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 two straight lines in the point of their intersection, if shall also be at right angles to the plane which... | |
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