In Euclidean plane geometry, a quadrilateral is a polygon with four edges (or sides) and four vertices or corners. Sometimes, the term quadrangle is used, by analogy with triangle, and sometimes tetragon for consistency with pentagon (5-sided), hexagon (6-sided) and so on. The origin of the word "quadrilateral" is the two Latin words quadri, a variant of four, and latus, meaning "side". A quadrilateral can be constructed uniquely if the lengths of its four sides and a diagonal are given. A quadrilateral can be constructed uniquely if the lengths of its three sides and two diagonals are given. A quadrilateral can be constructed uniquely if its two adjacent sides and three angles are given.