 | William Chauvenet - Geometry - 1888 - 346 pages
...At a 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... | |
 | 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... | |
 | 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...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.... | |
 | 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...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 lines.... | |
 | Edward Mann Langley, W. Seys Phillips - 1890 - 538 pages
...angles to all straight lines meeting it in that plane. PROP. 4.— If a straight line is at right angles to each of two straight lines at their point of intersection, it is at right angles to the plane in which they are. Let the st. line EF be xr to each of the two st. lines... | |
 | Edward Albert Bowser - Geometry - 1890 - 418 pages
...perpendicular. Proposition 3. Theorem. 500. If a nfrnight line is perpendicular to each of two ytraight lines at their point of intersection, it is perpendicular to the plane of those lines. Hyp. Let OP bcJ_to PA, PB at the pt. P. To prove OP is J_ to the plane MN of these lines.... | |
 | 1890 - 608 pages
...diminished by increasing its terms by the same magnitude. 2. If a straight line stand at right angles to each of two straight lines at their point of intersection, it is at right angles to the plane which passes through them. Two tetrahedra ABCD, afiyS are such that the... | |
 | 1891 - 644 pages
...first set as the first to the last of the other. If A : B=P : <?then A + B : A~ B — P + Q : P~ Q. 2. If a straight line is perpendicular to each of two...their point of intersection, it is perpendicular to their plane. The locus of a point equidistant from three straight lines which meet in a point, but... | |
 | Seth Thayer Stewart - Geometry, Modern - 1891 - 422 pages
...plane at the 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.... | |
 | Seth Thayer Stewart - Geometry - 1891 - 428 pages
...at H in this last plane. PROPOSITION II. 43O. Theorem : // a straight lint- is perpendicular to tivo straight lines at their point of intersection, it is perpendicular to the plane of those lines. Statement: Let AB be perpendicular to CK and EF at B. Prove that / 2 is perpendicular... | |
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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. 
