When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is called a right angle; and the straight line which stands on the other is called a perpendicular to it. A course of geometrical drawing - Page 2by William Schofield Binns - 1861Full view - About this book
| R. H. Warn, John G. Horner - Technology & Engineering - 2002 - 292 pages
...straight liue, B, makes the adjacent angles equal to one another, each of B Fig. 1. Fig. 2. the angles Ls **called a right angle, and the straight line which...stands on the other is called a perpendicular to it** (Fig. 2). 8. An obtuse angle is that which is greater than a right angle (Fig. 3). 9- An acute angle... | |
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