| George Washington Hull - Geometry - 1807 - 408 pages
...greater cuts off the greater distance from the foot of the perpendicular. PROPOSITION VII. THEOREM. 380. **If a straight line is perpendicular to each of two...of intersection, it is perpendicular to the plane** of those lines. Given — PO perpendicular to AO and BO at their intersection 0. To Prove — PO perpendicular... | |
| James Hayward - Geometry - 1829 - 218 pages
...position of this plane with respect to the line AB perpendicular to these two lines (197) ; we say — **If a straight line is perpendicular to each of two straight lines** drawn in a plane through its foot, it is perpendicular to every other straight line drawn through its... | |
| Euclid, James Thomson - Geometry - 1837 - 410 pages
...cannot but be a straight line.* Therefore, if two planes, &c. PROP. 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 line EF be perpendicular to each... | |
| Euclid, James Thomson - Geometry - 1845 - 382 pages
...planes AB, BC, 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... | |
| Dennis M'Curdy - Geometry - 1846 - 166 pages
...common section is a straight line. Recite def. 7,1. 4 Th. If a straight line stand at right angles **to each of two straight lines, at their point of intersection, it** will also be at right angles to the plane in which those straight lines are. Recite p 47 and 48 of... | |
| Elias Loomis - Conic sections - 1849 - 252 pages
...it is their 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... | |
| Royal Military Academy, Woolwich - Mathematics - 1853 - 400 pages
...be a right 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 said... | |
| George Roberts Perkins - Geometry - 1856 - 460 pages
...common to both of them ; that is, the intersection of the two planes is in a straight line. THEOREM Iv. **If a straight line is perpendicular to each of two...of intersection^ it is perpendicular to the plane** of these lines. Let AP be perpendicular to the two lines PB, PC, at their point of intersection P ;... | |
| Elias Loomis - Conic sections - 1858 - 256 pages
...it is their 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. Let the straight line AB be perpendicular... | |
| George Roberts Perkins - Geometry - 1860 - 474 pages
...common to both of them ; that is, the intersection of the two planes is in a straight line. THEOREM IV. **If a straight line is perpendicular to each of two...of intersection, it is perpendicular to the plane** of these lines. Let AP be perpendicular to the two* lines PB, PC, at their point of intersection P... | |
| |