| David Steel - 1805 - 392 pages
...each other. When a straight line AD standing upon another CB, makes angles ADC, ADB, on each side, equal to one another; each of these angles is called a Right Angle; and C J> B the line AD is said to be Perpendicular to the line CB. An angle is usually expressed by three... | |
| George Adams - Geometry - 1813 - 576 pages
...straight line AB, //<>-. 1 , plate 4, standing upon another CD, makes angles ABC, ABD, on each side equal to one another ; each of these angles is called a right angle ; and the line AB is said to be perpendicular to the line CD. It is usual to express an angle by three letters,... | |
| Euclid - 1822 - 222 pages
...sides. 1 1 . When a right line standing on another makes F,-g 3. the adjacent angles (ABC and ABD) equal to one another, each of these angles is called a right angle ; B ~ Pig. 4Fij7. 4SeeN, Steff, \ \ _\ T" Fij-6. iff. T. Pig. 8. Fvy. 8. F/j- 9. FS.7,, fig. 10. and... | |
| George Darley - Geometry - 1828 - 190 pages
...being conscious that it is a geometrical principle which directs their operations. LESSON II. DBF. VI. " If one right line, standing upon another, make...stands upon the other is called a perpendicular to it." TEACHER. The shortest way to know whether an angle, such as DCB, be a right one, is to produce one... | |
| Euclid - Euclid's Elements - 1833 - 216 pages
...the sides. 11. When a right line standing on another makes Fig. 3. the adjacent angles (ABC and ABD) equal to one another, each of these angles is called a right angle ; B and the right line, which stands on the other, is called a perpendicular to it. Fig. 1. 12. The... | |
| Euclides - 1846 - 292 pages
...ADG is equal to the angle BDG : But when a straight linc> standing upon another straight line, makes the adjacent angles equal to one another, each of these angles is a right angle ; therefore the angle BDG is a right angle : But BDF is also a right angle ; therefore... | |
| Euclides - 1852 - 48 pages
...line standing upon another right line makes the adjacent angles equal to one another, each of them is called a right angle ; and the right line which...stands upon the other is called a perpendicular to it ; thus, if the line AB, standing upon c D, makes the angles двф'c and ABD equal, each of them is... | |
| Euclides - Geometry - 1853 - 334 pages
...straight _____ line makes with that straight line, or with that straight line produced, if necessary, the adjacent angles equal to one another, each of these angles is denned to be a right angle ; and each of the straight lines is defined to be perpendicular to the other.... | |
| Euclides - 1855 - 270 pages
...equal (I. 8) to the angle GD B. But when a straight line standing upon another straight line makes the adjacent angles equal to one another, each of these angles is a right angle (I. Def. 10). Therefore the angle GDB is a right angle. But FDB is likewise (Const.)... | |
| Robert Potts - Geometry, Plane - 1860 - 380 pages
...CB, is called the angle DBC, or CBD. X. When a straight line standing on another straight line, makes the adjacent angles equal to one another, each of these angles is called a right angle ; and the straight line which stands on the other is called a perpendicular to it. XL An obtuse angle is that... | |
| |