Of three-sided Figures: an Equilateral Triangle is that which has three equal Sides.
DEFINITION XXV.
An Isosceles Triangle, is that which has only two Sides equal.
DEFINITION XXVI.
A Scalene Triangle, is that which has three unequal Sides.
DEFINITION XXVII.
A Right-angled Triangle is that which has a Right Angle.
DEFINITION XXVIII.
An Obtuse-angled Triangle is that which has an Obtuse Angle.