Area Calculator. Online Conversion - Convert just about anything to anything else. Free Online Math Calculator and Converter. Circle. A circle can be defined as the curve traced out by a point that moves so that its distance from a given point is constant.
Terminology[edit] History[edit] Circular piece of silk with Mongol images The circle has been known since before the beginning of recorded history. Triangles. A plane triangle is an object having 3 straight sides in 2-dimensional space.
(Triangles in other spaces, for example spherical triangles, are not treated here.) Triangles have 3 sides, 3 vertices (the points where the sides meet), and 3 angles.