 | Euclides - 1864 - 262 pages
...Wherefore, if a side of any triangle be produced, &c. QED COR. 1. All the interior angles of any rectilineal figure together with four right angles, are equal to twice as many right angles as the figure has sides. For any rectilineal figure ABCDE can be divided into as many triangles as the figure has sides,... | |
 | Robert Potts - 1865 - 528 pages
...angles of the triangles are equal to twice as many right angles as the figure has sides ; therefore all the angles of the figure together with four right...equal to twice as many right angles as the figure has sides. Con. 2. All the exterior angles of any rectilineal figure, made by producing the sides successively... | |
 | Euclides - 1865 - 402 pages
...1.) Wherefore, if a side of a triangle, &c. QED Cor. 1. All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. DEMONSTRATION For, any rectilineal figure ABCDE can, by drawing straight lines from a point... | |
 | William Harris Johnston - 1865 - 478 pages
...32nd prop, of Euclid, Book I., it is demonstrated that, <> all the interior angles of any rectilinear figure, together with four right angles, are equal to twice as many right angles as the figure has sides." Hence, the sum of all the angles of a rectilinear figure will be found by taking twice as many... | |
 | Euclides - 1865 - 80 pages
...figure has sides wanting four right angles. Let ABODE be any given rectilineal figure, all its interior angles are equal to twice as many right angles as the figure has sides wanting four right angles. From F, a point within the figure, draw the straight lines AF, BF,... | |
 | Samuel Alsop - Surveying - 1865 - 440 pages
...and B ABC + BAC + ACB = two right angles. (32.1.) 76. The interior angles of any rectilineal figure are equal to twice as many right angles as the figure has sides, diminished by four right angles. The interior angles of a quadrilateral are therefore equal... | |
 | Euclid, Isaac Todhunter - Euclid's Elements - 1867 - 426 pages
...triangles, that is, together with four right angles. [I. 15. Corollary 2. Therefore all the interior angles of the figure, together with four right angles,...equal to twice as many right angles as the figure has sides. COROLLARY 2. All the exterior angles of any rectilineal figure are together equal to four right... | |
 | William Thomas Brande, George William Cox - Encyclopedias and dictionaries - 1867 - 1090 pages
...polygons, the first corollary to his prop. 32, book i. (according to which all the interior angles, together with four right angles, are equal to twice as many right angles as the figure hns sides), is also true for concave polygons. His second corollary, however, according to which the... | |
 | Euclid, Isaac Todhunter - Euclid's Elements - 1867 - 424 pages
...Wherefore, if a side of any triangle &c. Q EB COROLLARY 1. All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as thejigure has side.". For any rectilineal figure ABCDE can be divided into as many triangles as the... | |
 | William Thomas Brande, George William Cox - Encyclopedias and dictionaries - 1867 - 1090 pages
...polygons, the first corollary to his prop. 32, book i. (according to which all the interior angles, together with four right angles, are equal to twice as many right angles as tie figure has sides), is also true for concave polygons. His second corollary, however, according... | |
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F, which is the common vertex of the triangles ; that is, together with four right angles. Therefore all the angles of the figure, together with four right angles, are equal to twice as many right angles as the figure has sides. 
