 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.  A system of popular trigonometry - Page iiiby George Darley - 1835Full view - About this book
 | Webster Wells - 1909 - 154 pages
...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
...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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