Page:Euclid's Elements 1714 Barrow translation.djvu/16

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XXVI. Of thee Trilateral figures, a right-angled Triangle is that which has one right angle; as the Triangle A.

XXVII. An Amblygonium, or obtue-angled Triangle, is that which has one angle obtue; as B.



XXVIII. An Oxygonium, or acute-angled Triangle, is that which has three acute angles; as C.

An Equiangular, or equal-angled figure is that whereof all the angles are equal. Two figures are equiangular, if the everal angles of the one figure be equal to the everal angles of the other. The ame is to be undertood of Equilateral figures.



XXIX. Of Quadrilateral, or four-ided figures, a Square is that whoe ides are equal, and angles right; as ABCD.



XXX. A figure on the one part longer, or a long quare, is that which hath right angles, but not equal ides; as ABCD.