 | Cambridge (England) - 1804 - 476 pages
...both by vulgar fractions and by decimals. 2. ^Prove that if a straight line stand at right arfgles to each of two straight lines in the point of their intersection, it will be at right angles to the plane that passes through them. 3. Define a rhombus; and prove that... | |
 | 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...the point of their intersection, it shall also be at ri^ht angles to the plane which passes through them, that is, to the plane in which they are. Let the... | |
 | 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...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... | |
 | Euclid - Geometry - 1810 - 554 pages
...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...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... | |
 | Euclides - 1814 - 560 pages
...DE: Therefore AF is perpendicular to each of the straight Hues GH, DC. But if a straight line stands at right angles to each of two straight lines in the point of their intersection, it shall »lso be at right angles to the plane passing through them. But the plane passing through ED, GH, is... | |
 | Euclides - 1816 - 588 pages
...DE : ThereforeAFis 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...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 i therefore AF is perpendicular... | |
 | John Playfair - Circle-squaring - 1819 - 350 pages
...common to the 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...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 - 1819 - 354 pages
...common to the plnnes AB and BC, or v 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 too straight lines in the point of their intersection, it will also be at right angles to the plane... | |
 | 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...straight lines in the point of their intersection, it will be at right angles to the plane that passes through them. 3. Define a rhombus; and prove that... | |
 | 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... | |
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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. 
