AB, CD. In like manner, it may be proved, that FE makes right angles with every straight line which meets it in that plane. But a straight line is at right angles to a plane when it makes right angles with every straight line which meets it in that plane... Books 10-13 and appendix - Page 279by Euclid, Sir Thomas Little Heath, Johan Ludvig Heiberg - 1908Full view - About this book
| William Thomas Read - Nautical astronomy - 1869 - 154 pages
...taken, the line joining those points lies wholly in that surface. 2. A straight line is said to be **at right angles to a plane, when it makes right angles with** every line which meets it in that plane. 3. The inclination of a plane to a plane, is the acute angle... | |
| Euclides - 1874
...it may be proved that FE makes right angles with every other straight line meeting it in that plane. **But a straight line is at right angles to a plane when it makes right angles with** every straight line meeting it in that plane (XI. Def. 3) ; therefore . 9. EF is at right angles to... | |
| Robert Potts, Thomas Kirkland - Geometry, Plane - 1876 - 403 pages
...it may be proved, that FE makes right angles with every straight line which meets it in that plane. **But a straight line is at right angles to a plane when it makes right angles with** every straight line which meets it in that plane : (XI. def. 3.) therefore EF is at right angles to... | |
| Isaac Todhunter - Euclid's Elements - 1880 - 400 pages
...and thickness. 2. That which bounds a solid is a superficies. 3. A straight line is perpendicular, or **at right angles, to a plane, when it makes right angles with** every straight line meeting it in that plane. 4. A plane is perpendicular to a plane, when the straight... | |
| Euclid - 1883
...and thickness. 2. That which bounds a solid is a superficies. 3. A straight line is perpendicular, or **at right angles, to a plane, when it makes right angles with** every straight line meeting it in that plane. 4. A plane is perpendicular to a plane, when the straight... | |
| Edward Mann Langley, W. Seys Phillips - Mathematics - 1890 - 515 pages
...thickness. 2. That which bounds a solid is a 'superficies.' 3. A straight line is 'perpendicular,' or **'at right angles,' to a. plane, when it makes right angles with** every straight line meeting it in that plane. 4. A plane is ' perpendicular,' or at right angles, to... | |
| Morris Kline - Mathematics - 1990 - 428 pages
...which has length, breadth, and depth. Definition 2. An extremity of a solid is a surface. Definition 3. **A straight line is at right angles to a plane when...with all the straight lines which meet it and are in** the plane. Definition 4. A plane is at right angles to a plane when the straight lines drawn, in one... | |
| Robert Catesby Taliaferro, Euclid, Martin Luther D'Ooge, Archimedes, Sir Thomas Little Heath, Nicomachus (of Gerasa.), Apollonius (of Perga.) - 1956 - 848 pages
...1. A solid is that which has length, breadth, and depth. 2. An extremity of a solid is a surface. 3. **A straight line is at right angles to a plane, when...with all the straight lines which meet it and are in** the plane. '4. A plane is at right angles to a plane when the straight lines drawn, in one of the planes,... | |
| ...(§ 60). Straight Lines which meet parallel planes are cut by these planes in the same ratio (§ 61). **A straight line is at right angles to a plane when it** is at right angles to every line meeting it in the plane (§§ 62-64). Angle between two planes (§65).... | |
| ...dihedral angle is that made by the under surface of the HP and the front surface of the VP (202). * **A straight line is at right angles to a plane, when it** is at right angles to every straight line in the plane that passes through their point of section.... | |
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