| Euclid, James Thomson - Geometry - 1845 - 380 pages
...cannot but be a straight line.* Therefore, &c. Puor. 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 lineEF be perpendicular to each... | |
| Scottish school-book assoc - 1845 - 434 pages
...common section of the two planes is a straight line. GEOMETRY OF PLANES. PBOPOSITION LXXX — THEOREM. **If a straight line stand at right angles to each of two** traight lines in the point of their intersection, it will also e at right angles to the plane in which... | |
| John Playfair - Euclid's Elements - 1846 - 332 pages
...therefore common to the planes AB and BC, or it is the common sectioa 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 - 1846 - 292 pages
...planes AB, BC, cannot but be a straight line. Wherefore, If two planes %c. ct. KD 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... | |
| 1846
...too, by Euclid with an elegance fully equal to that by which any other author has proved it,) that **"if a straight line stand at right angles to each of two** stright lines at their point of intersection, it shall also be at right angles to every other line... | |
| Perry Fairfax Nursey - Industrial arts - 1846
...too, by Euclid with an elegance fully equal to that by which any other author has proved it,) that **"if a straight line stand at right angles to each of two** stright lines at their point of intersection, it shall also be at right angles to every other line... | |
| Samuel Hunter Christie - 1847 - 172 pages
...section of the planes AB, BC, cannot but be a straight line: which was to be proved. 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... | |
| Elias Loomis - Conic sections - 1849 - 252 pages
...common section. Hence, if two planes, &c. PROPOSITION IV. THEOREM. If a straight line be perpendicular **to each of two straight lines at their point of intersection, it will** be perpendicular to the plane in which these lines are. Through B draw any line BG, in the plane MN;... | |
| John Playfair - Euclid's Elements - 1849 - 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** hnes in the point of their intersection, it will also be at right angles to the plane in which these... | |
| Royal Military Academy, Woolwich - Mathematics - 1853
...angle, the planes are said to be perpendicular to one another. 5. If a straight line be perpendicular **to each of two straight lines at their point of intersection, it** is said to be perpendicular to the plane passing through those two lines. Conversely, the plane is... | |
| |