 A straight line is said to be perpendicular to a plane when it is perpendicular to every straight line which passes through its foot in that plane, and the plane is said to be perpendicular to the line.  Elementary Course of Geometry ... - Page 1by Charles William Hackley - 1847 - 103 pagesFull view - About this book
 | George Bruce Halsted - Geometry - 1904 - 322 pages
...(by 43) APCD .-.PD=P'D; .'.(by 58) APBD=AP'DB. .-. 4PBD^4P'BD; .\BP±BD. 334. Definition. A straight is said to be perpendicular to a plane when it is perpendicular to every straight in that plane which passes through its foot, — that is, the point it has in common... | |
 | George Bruce Halsted - Geometry - 1904 - 324 pages
...&PCD=AP'CD. :.PD=P'D; .'.(by 58) &PBD=&P'DB. :. 4PBD=4P'BD; .-.BPJ-BD. 334. Definition. A straight is said to be perpendicular to a plane when it is perpendicular to every straight in that plane which passes through its joot, — that is, the point it has in common... | |
 | Frank Moulton Saxelby - Mathematics - 1905 - 460 pages
...the lengths of the traces we have 192. Measurement of Angles between Straight Lines and Planes. — A straight line is said to be perpendicular to a plane when it is perpendicular to every straight line in that plane. 323 lines drawn one in each plane perpendicular to the line of intersection... | |
 | Webster Wells - Geometry - 1908 - 336 pages
...349. Defs. If a straight line meets a plane, the point of intersection is called the foot of the line. A straight line is said to be perpendicular to a plane when it is perpendicular to every straight line drawn in the plane through its foot. A straight line is said to be parallel to... | |
 | Walter Percy Workman - Geometry - 1908 - 228 pages
...room are parallel planes ; the flat top of a table standing in a room is parallel to the floor, etc. (3) A straight line is said to be perpendicular to a plane if it is perpendicular to every line in the plane which meets it. (See Fig. 517.) A straight line perpendicular... | |
 | Webster Wells - 1909 - 154 pages
...a transversal, the alternateinterior angles are equal.) § 75. 6. Z EPX and Z XQH are right angles. (A straight line is said to be perpendicular to a plane, when it is perpendicular to every straight .line drawn in the plane through its foot.) § 349. 7. Hence, A EPX = A XQH. §90. 8.... | |
 | Charles Austin Hobbs - Geometry, Solid - 1921 - 216 pages
...two intersecting lines are perpendicular or oblique to each other. RELATIONS OF LINES AND PLANES A line is said to be perpendicular to a plane when it is perpendicular to every line in the plane drawn through its foot; at the same time the plane is said to be perpendicular... | |
 | Walter Burton Ford, Charles Ammermann - Geometry, Modern - 1923 - 406 pages
...Plane. The point where a line in space intersects a plane is called the foot of the line on that plane. A straight line is said to be perpendicular to a plane when it is perpendicular to every straight line that can be drawn in the plane through its foot. Fio. 178 (a) FIG. 178 (ft) Thus,... | |
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