1 This implies that the other two sides are of equal length, and that the diagonals are of equal length. 2  An alternative definition is: a quadrilateral with an axis of symmetry bisecting one pair of opposite sides. 3  Trapezium (NAm.): no sides are parallel.
An enumeration date commonly refers to the official or control date set for a particular enumeration event such as a census. The official enumeration date may vary from one enumeration to the next. The enumeration date is a control function for collecting data over a broad space of time. All data collected is based on its validity as of a single date, no matter what date the information is taken within the enumeration period.
14.6 Duration of enumeration refers to the time taken to conduct the census enumeration. In the case of a population census de facto, the entire operation is ideally completed in one day, at least in urban areas, and in just a few days in rural areas. This is not possible in the case of an agricultural census.