Short, but yet plain elements of geometry shewing how by a brief and easie method, most of what is necessary and useful in Euclid, Archimedes, Appollonius, and other excellent geometricians, both ancient and modern, may be understood / written in French by F. Ignat. Gaston Pardies. And render'd into English, by John Harris.
- Ignace-Gaston Pardies
- Date:
- 1734
Licence: Public Domain Mark
Credit: Short, but yet plain elements of geometry shewing how by a brief and easie method, most of what is necessary and useful in Euclid, Archimedes, Appollonius, and other excellent geometricians, both ancient and modern, may be understood / written in French by F. Ignat. Gaston Pardies. And render'd into English, by John Harris. Source: Wellcome Collection.
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![N. B, The Line A B may be called the Deferi- ~kentyand AE the Dirigent, becaufe the latter directs the Motion of the former. 6. A Triangle, as 4, which hath bat AE one Right Angle, isa Righr-an- gled Triangle sifithaveone An- — gle Obtufe, ’tis called an Obtu(e- | angled one, as à 3 and if all its 18 three Angles are Acute, *tis call: Oh SENS ed an Acute-angled ‘Triangle, 2 ROE as ¢ y. If a Triangle have all its three Sides unequal, ’tis called a Scalene,as 4. Uf it hath two Sides a ee équal,’tiscalled an /O/celes, ase; Pf And if all the three Sides are e- * a io by qual, “tis called an Zqwilareral - ZEN one, asf. ae §. When two Sides of a Triangle are confidered, they may be called its Legs, and the third Side may then be called the Bae. But any one Side may be called the Bae, tho we ufually ana moft fro- perly call that fo, which lies parallel to the Horizon, ana which is next to us. a __ 9. In every Triangle, the three Angles, taken to: gether, are equal to two Right ones. i 2048 Let the Triangle be a/c: I fay, that the Angle a added to thé Angle c) added tothe Angle 2 (or the Sum of allthree) are equal to two Right ones. For let Ze be drawn parallel to the Bafe ac, then will thofe two parallel Lines be cut by the Line 4c 3 and | confequently the alternate Angles c and 4 will be equal to each other (by x. 31.) Moreover the Line Ÿ 4 falling on, or cutting the fame Parallels _ acand #6, will make the two internal Angles on eo a € the . 1.9, . * vd LC] ° oe. “ns 0-0 @ À d te. |](https://iiif.wellcomecollection.org/image/b33021995_0029.jp2/full/800%2C/0/default.jpg)
