The form of the proglottides is most generally a rhombic or trapezoidal figure.
This is called the trapezoidal or chordal area, and will be denoted by C1.
The alternative method, therefore, consists in taking a simple formula, such as the trapezoidal rule, and correcting it to suit the mutual relations of the differences.
As the measurements can only be rough, the trapezoidal rule is the most appropriate in ordinary cases.
The terramara, in spite of local differences, is of typical form; it is a settlement, trapezoidal in form, built upon piles on dry land protected by an earthwork strengthened on the inside by buttresses, and encircled by a wide moat supplied with running water.
