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. A quadrilateral is simply a 4 sided polygon. There are 2 special subsets of polygons. The first is a trapezoid, which has 1 pair of opposite sides being parallel. If the other two pairs of base angles and opposite sides are congruent, then the trapezoid is isosceles. The four sides in a trapezoid are NEVER congruent. The other special subset of quadrilaterals is parallelograms. A parallelogram has opposite sides being both congruent and parallel. Opposite angles are also congruent and consecutive angles are supplementary (= 180). Subsets of parallelograms are rectangles, where all the angles are right angles (=90) and rhombuses, which DO have all 4 sides being congruent. A special quadrilateral that is BOTH a rhombus and a rectangle is the square. In short, only squares and rhombuses have 4 congruent sides. The rest do not.