Some dyad was then produced, which the respondent did not know to be a dyad; accordingly he did not know it to be even.
The respondent was asked, Do you know that every dyad is even?
Here there is a single plane of symmetry perpendicular to which is a dyad axis; there is also a centre of symmetry.
For either the dyad is not One; or else the monads included therein are not monads ἐντελεχείᾳ (a. 14).
Here there are three dyad axes, but no planes of symmetry and no centre of symmetry.
There being six pairs of parallel edges on an octahedron, there are consequently six dyad axes of symmetry.
Here there is only one dyad axis in which two planes of symmetry intersect.
The other elements of symmetry (six dodecahedral planes and six dyad axes) are the same as in the last class.
Six dyad axes of two kinds are perpendicular to the hexad axis.
There are five axes of symmetry, one tetrad and two pairs of dyad, each perpendicular to a plane of symmetry.
dyad dy·ad (dī'ād', -əd)
Two individuals or units regarded as a pair, such as a mother and a daughter.
A divalent atom or radical.
One pair of homologous chromosomes resulting from the division of a tetrad during meiosis.