Books Books 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. Elements of Geometry: With Practical Applications to Mensuration - Page 170
by Benjamin Greenleaf - 1868 - 320 pages ## Examination papers, and division lists, &c. [afterw.] General certificate of ...

Oxford univ, local exams - 1880 - 394 pages
...sum of the rectangles contained by its opposite sides. 12. If a straight line stand at right angles to each of two straight lines at their point of intersection, it shall also be at right angles to the plane which passes through them, that is, to the plane in which... ## The Cambridge Examiner, Volume 2

Education, Higher - 1882 - 498 pages
...point of division is the centre of the inscribed circle. 16. If a straight line stand at right angles to each of two straight lines at their point of intersection, it shall also be at right angles to the plane which passes through them, that is, to the plane in which... ## A Treatise on Elementary Geometry: With Appendices Containing a Collection ...

William Chauvenet - Geometry - 1884 - 386 pages
...perpendicular. PROPOSITION V.— THEOREM. 13. If a straight line is perpendicular to each of two strair/ht lines at their point of intersection, it is perpendicular to the plane of those lines. Let AP be perpendicular to PB and PC, at their intersection P; then, AP is perpendicular... ## Elements of Geometry and Trigonometry from the Works of A.M. Legendre ...

Charles Davies, Adrien Marie Legendre - Geometry - 1885 - 538 pages
...straight line ; 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... ## Chauvenet's Treatise on Elementary Geometry

William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...given point in a plane one perpendicular can be erected to the plane, and but one. PROPOSITION IV. If a straight line is perpendicular to each of two...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... ## Chauvenet's Treatise on Elementary Geometry

William Chauvenet - Geometry - 1888 - 346 pages
...given point in a plane one perpendicular can be erected to the plane, and but one. PROPOSITION IV. If a straight line is perpendicular to each of two straight lines lit their point of intersection, it is perpendicular to the plane of tiiose lines. Corollary I. At... ## Calendar

University College, Dundee - 1889 - 358 pages
...QA. BB ; and PQR lie on a straight line if BP. CQ. AR = CP. AQ. BR ; attention being paid to sign. 9. If a straight line is perpendicular to each of two straight lines where they meet, prove that it is perpendicular to the plane in which they lie. 10. If two straight... ## The Elements of Plane and Solid Geometry: With Numerous Exercises

Edward Albert Bowser - Geometry - 1890 - 420 pages
...the plane, is a circle whose centre is the foot of (he perpendicular. Proposition 3. Theorem. 500. If a straight line is perpendicular to each of two...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... ## The Elements of Plane and Solid Geometry ...

Edward Albert Bowser - Geometry - 1890 - 414 pages
...from the foot of the perpendicular.SOLID GEOMETRY. Proposition 3. Theorem. '*• 500. If a ftraight line is perpendicular to each of two straight lines...of intersection, it is perpendicular to the plane of those lines. Hyp. Let OP beJ_to PA, PB at the pt. P. To prove OP is J_ to the plane MN of these... 