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... figure, together with four right angles, are equal to twice as many right angles as the figure has be divided into as many triangles as the figure has sides, by drawing straight lines from a point F within the figure to each of its angles.
The elements of plane geometry, from the Sansk. text of Ayra Bhatta, ed. by ... - Page 40
by Āryabhaṭa - 1878

Elements of Geometry and Trigonometry Translated from the French of A.M ...

Charles Davies - Trigonometry - 1849 - 372 pages
...to two right angles, taken as many times, less two, as the polygon has sides (Prop. XXVI.); that is, equal to twice as many right angles as the figure has sides, wanting four right angles. Hence, the interior angles plus four right Let the sides of the polygon...

Reports on Elementary schools

Her MAjesty' Inspectors of schools - 1850 - 912 pages
...Section.) Section I. 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. 2. If the square described upon one side of a triangle be equal to the sum of the squares described...

Minutes ...: Correspondence, Financial Statements, Etc., and ..., Volume 2

Great Britain. Committee on Education - 1850 - 942 pages
...Section.) Section I. 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. 2. If the square described upon one side of a triangle be equal to the sum of the squares described...

The Church of England quarterly review, Volume 28

1850 - 524 pages
...proposition 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 : and the dictum is equally true, too, in moral science — only in any particular case to dogmatize...

Elementary Geometry: With Applications in Mensuration

Charles Davies - Geometry - 1850 - 238 pages
...triangles is equal to two right angles (Th. xvii) : hence, the sum of the angles of all the triangles is equal to twice as many right angles as the figure has sides. But the sum of all the angles about the point P is equal to four right angles (Th. ii. Cor. 3) ; and...

Elementary Geometry: With Applications in Mensuration

Charles Davies - Geometry - 1850 - 218 pages
...triangles is equal to two right angles (Th. xvii) : hence, the sum of the angles of all the triangles is equal to twice as many right angles as the figure has sides. But the sum of all the angles about the point P is equal to four right angles (Th. ii. Cor. 3) ; and...

A Manual of Surveying for India, Detailing the Mode of Operations on the ...

Sir Henry Edward Landor Thuillier - Surveying - 1851 - 826 pages
...drawing straight lines from a point F within the figure to each of its angles. And, by this Theorem, all the angles of these triangles are equal to twice as many right angles as there are triangles, that is, as there are sides of the figure : and the same angles are equal to the...

Plane trigonometry. [With] Solutions of examples. Appendix &c., to adapt the ...

John William Colenso (bp. of Natal.) - 1851 - 382 pages
...Cor. 1, that ' 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.' Hence if и be the number of sides of any rectilineal figure, we have the sum of its n angles + 4 x...