Books Books
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.
The Elements of Euclid; viz. the first six books, together with the eleventh ... - Page 30
by Euclides - 1814

## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

John Playfair - Circle-squaring - 1819 - 333 pages
...to all the angles of the figure, together with four right angles, that is, the angles of the figure are equal to twice as many right angles as the figure has sides, wanting four. COR. 2. All the exterior angles of any rectilineal figure are tegether equal to four...

## The First Six Books with Notes

Euclid - 1822 - 179 pages
...therefore equal to B AE and EAC. Cor. 6. All the internal angles of any rectilineal figure, ABCDE, together with four right angles, are equal to twice as many right angles as the figure has sides. Take any point F within the figure and draw the right lines FA, FB, FC, FD, and FE. There are formed...

## Euclid's Elements of Geometry: The Six First Books. To which are Added ...

Euclid, Rev. John Allen - Astronomy - 1822 - 494 pages
...as many right angles, except four, as the figure has sides ; and all tbe angles of these triangles are equal to twice as many right angles as the figure has sides (32. 1 /CM.), therefore the angles of these triangles which are at their common vertex A, being those...

## Euclid's Elements of Geometry: The Six First Books. To which are Added ...

Euclid, Rev. John Allen - Astronomy - 1822 - 494 pages
...two right angles [13. 1} ; therefore all the exterior and interior angles of the figure are together equal to twice as many right angles as the figure has sides ; but the interior angles are equal to twice as many right angles, except four, as the figure has sides...

## A Course of Mathematics: For the Use of Academies, as Well as Private ...

Charles Hutton - Mathematics - 1822
...triangles, is equal to two right angles (th. 17) ; therefore 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, which are so / many of the angles of the triangles,...

## A treatise on navigation, and nautical astronomy

Edward Riddle - Nautical astronomy - 1824 - 551 pages
...twice as many right angles as the figure has sides ; or the interior angles of the figure, themselves, are equal to twice as many right angles as the figure has sides, wanting four right angles. QED Cor. 1. All the interior angles of any quadrilateral figure are together...

## A Popular Course of Pure and Mixed Mathematics ...: With Tables of ...

Peter Nicholson - Mathematics - 1825 - 372 pages
...that is, (2. Cor. 15. 1 .) together with four right angles. Therefore all the angles of the figure, together with four right angles, are equal to twice as many right angit's as the figure has sides. Cor. 2. All the exterior angles of any rectilineal figure are together...

## Elements of Arithmetic, Algebra, and Geometry

George Lees - 1826
...to all the angles of the figure, together with four right angles ; that is, the angles of the figure are equal to twice as many right angles, as the figure has sides wanting four. PROP. XIII. THEOREM. If two triangles, BAG, EOF, have two angles, BAG, ABC, and a side...