dyad

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?

When you say a line, do you mean a dyad in length Form in Matter?

For either the dyad is not One; or else the monads included therein are not monads ἐντελεχείᾳ (a. 14).

Here there is only one dyad axis in which two planes of symmetry intersect.

They are parallel to the edges of the cube, and in the different classes coincide either with tetrad or dyad axes of symmetry.

Here there is a single plane of symmetry perpendicular to which is a dyad axis; there is also a centre of symmetry.

There being six pairs of parallel edges on an octahedron, there are consequently six dyad axes of symmetry.

Here there are three similar planes of symmetry intersecting in the triad axis; there are no dyad axes and no centre of symmetry.

There are five axes of symmetry, one tetrad and two pairs of dyad, each perpendicular to a plane of symmetry.