这个和弦由三个音符组成，形成一个三音结构。

The chord consists of three notes, forming a ___triadic structure.

这个合作协议是由三家公司以三方协议形式签署的。

The cooperative agreement was signed in a ___triadic arrangement between three companies.

这首曲子使用了大量的三和弦进行。

The song uses many ___triadic progressions.