Word Origin & History. epicene mid-15c., originally a grammatical term for nouns that may denote either gender, from L. epicoenus common, from Gk. Extended sense of characteristic of both sexes first recorded in English c.1600; that of effeminate 1630s.
A parallelogram is a quadrilateral with two pairs of parallel sides. Equivalent conditions are that opposite sides are of equal length; that opposite angles are equal; or that the diagonals bisect each other. Parallelograms also include the square, rectangle, rhombus and rhomboid. Rectangle: all four angles are right angles. 2  An equivalent condition is that the diagonals bisect each other and are equal in length. 3  Informally: a box or oblong (including a square). 4  Square (regular quadrilateral): all four sides are of equal length (equilateral), and all four angles are right angles.
No. In order for a quadrilateral to be a trapezoid, it must have exactly one pair of parallel sides. A right trapezoid, therefore, has exactly one pair of right angles. However a square would be a right parallelogram (which is the current definition of a rectangle). In the UK, the word trapezoid refers to a quadrilateral with no sides parallel. They use the word trapezium to refer to what Canadians call a trapezoid. To make matters worse, North Americans call a quadrilateral with no parallel sides a trapezium. Here's a summary.