A triad or triplet is a music figure (a tuplet) consisting of three notes having a duration of two notes. Three triad notes of 1/8 have a duration of 1/2, so each one thus has 1/6 duration.
An ordinary note is transformed into (shorted with 2/3) a triad note using <F5> and back to an ordinary note using <F6>
A triad may contain rests as in:
Combinations of durations are allowed within a triad as long as its summed duration is a simple note length.
Triad notes are entered by selecting the base-duration in combination with the triad-button on the button bar