| John Playfair - Trigonometry - 1806 - 311 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 which these lines... | |
| Robert Simson - Trigonometry - 1806 - 518 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 passes through... | |
| John Mason Good - 1813
...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 passes through... | |
| Euclides - 1814
...AB, N BC, cannot but be a straight line. Wherefore, if two planes, &c. QED PROP. IV. THEOR. SeeN. IP **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-them,... | |
| Euclides - 1816 - 528 pages
...planes AB, BC, cannot but be a straight line. Wherefore, if two planes, &c. QED PROP. IV. THEOR. SeeN. **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 - Circle-squaring - 1819 - 333 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 which these lines... | |
| Mathematics - 1821 - 425 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 through them.... | |
| Robert Simson - Trigonometry - 1827 - 513 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 passes through... | |
| Pierce Morton - Geometry - 1830 - 272 pages
...which joins any two of its points, that is, it is a straight line. Therefore, &c. PROP. 3. (Eue. xi. **4.) 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 every other straight... | |
| Euclid - 1835 - 513 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 passes through... | |
| |