rhomboid is a shape with diagonal adjacent sides that are not equal in length.
rhomboid is a shape with diagonal adjacent sides that are not equal in length.
shapes with diagonal adjacent sides that are not equal in length?
rhomboid
the three-dimensional counterpart of a parallelogram is a parallelepiped.









































the etymology (in greek παραλληλ-όγραμμον, a shape "of parallel lines") reflects the definition.









































section::::special cases.









































bullet::::- rhomboid – a quadrilateral whose opposite sides are parallel and adjacent sides are unequal, and whose angles are not right angles









































bullet::::- rectangle – a parallelogram with four angles of equal size (right angles).









































bullet::::- rhombus – a parallelogram with four sides of equal length.









































bullet::::- square – a parallelogram with four sides of equal length and angles of equal size (right angles).









































section::::characterizations.
parallelogram
bullet::::- in rin-chen lha-mo's work "we tibetans" (1926), she states that "the longer the sequence you can [capture] . . . the better and the sequence is not broken by going around a corner, thus:". this has been interpreted to mean that it may be possible to capture a corner piece, or a line(s) of pieces that occupy a portion of two adjacent sides of the board (hence at most one corner piece) by flanking them on two opposite ends provided there is no vacant space between any of the pieces, and rin-cen lha-mo actually provides an illustration showing just that. this rule is useful because it's generally difficult to perform these types of captures using the regular custodian method. however, some critics have debated whether this rule can be applied to any position on the board, or just with corner pieces. rin-chen lha-mo does however specifically state "...going around a corner...", and provides an illustrative example of pieces strictly going around a corner of the board. lastly, rin-chen lha-mo does not specify whether or not the two pieces used to flank the captured pieces must occupy the same two adjacent sides that the captured pieces are occupying, although based upon the illustrative example she gave, she may have been attempting to suggest that. for example, in the beginning of the game, can one player attempt to capture the other player's 14 pieces as it is initially laid out using this modified custodian method? she also does not specify if (any of) the two pieces can be corner pieces (but opposite one another on the board if both are corner pieces) since these two corner pieces would not only occupy the same adjacent sides of the captured pieces, but also the remaining two other sides.
ming mang (game)