 | Adrien Marie Legendre - Geometry - 1874 - 500 pages
...which was to be proved. PROPOSITION IV. THEOREM. Jf a straight line is perpendicular to two straight lines at their point of intersection, it is perpendicular to the plane of those lines. Let JOT be the plane of the two lines BB, (7(7, and let AP be perpendicular to these lines... | |
 | William Guy Peck - Conic sections - 1876 - 412 pages
...a plane. PROPOSITION III. THEOREM. If a straight line is perpendicular to each of two intersecting lines at their point of intersection, it is perpendicular to the plane of those lines. Let AQ and DQ be two lines in the plane KL, and let PQ be perpendicular to both ; then... | |
 | 1876 - 646 pages
...area what one has the least perimeter? 5. If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of those lines. 6. A triangular pyramid is one-third of a triangular prism of tbe same base and altitude.... | |
 | Cornell University - 1880 - 868 pages
...ellipse, the eccentricity of a hyperbola. 2. If a straight line be perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of those lines. 3. The lateral area of a regular pyramid is equal to the product of the perimeter of its... | |
 | Charles Davies, Adrien Marie Legendre - Geometry - 1885 - 538 pages
...which was to be proved. PROPOSITION IV. THEOREM. // a straight line is perpendicular to two straight lines at their point of intersection, it is perpendicular to the plane of those lines. BOOK VI. pendicular to every straight line of the plane which passes through P, and consequently,... | |
 | William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...the plane, and but one. PROPOSITION IV. If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of those lines. Corollary I. At a given point of a straight line, one plane can be drawn perpendicular... | |
 | Edward Albert Bowser - Geometry - 1890 - 420 pages
...perpendicular. Proposition 3. Theorem. 500. If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of those lines. Hyp. Let OP be_]_to PA, PB at the pt. P. To prove OP is J_ to the plane MN of these lines.... | |
 | Seth Thayer Stewart - Geometry, Modern - 1891 - 422 pages
...greater distance is the longer line. PROP. II. If a straight line is perpendicular to two straight lines at their point of intersection, it is perpendicular to the plane of those lines. PROP. III. If two straight lines are perpendicular to the same plane, they are parallel.... | |
 | George Albert Wentworth - Geometry - 1892 - 468 pages
...PLANES. PROPOSITION II. THEOREM. 472. // a straight line is perpendicular to each of two other straight lines at their point of intersection. it is perpendicular to the plane of the two lines. Let AB be perpendicular to BC and BD at B. To prove AB perpendicular to the plane MN of these Proof.... | |
 | Yale University - 1892 - 200 pages
...when these sides are at right angles. 7. If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of these lines. 8. Define symmetrical polyhedral angles. Illustrate the definition by a figure. 9. Define... | |
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If a straight line is perpendicular to each of two other straight lines at their point of intersection, it is perpendicular to the plane of the two lines. 
