The Triolet Is shorter than the other forms , comprising only 8 lines. Of those 8, the poet only needs to write 5 original lines as the form builds on a rentrement - first-line refrain - and further repetition of the second line. These also initiate the only two rhymes of the poem, with all other lines either repeating or rhyming with the first two.
Originally, lines would be in Iambic Tetrameter - four sets of two beats with a weak-strong rhythm - though in more recent cases and through its English-language revival, this has been mostly left behind so that the poet can choose their own metre.
Here is a closer look at the layout, showing the rhymes and refrains, where like letters are rhyming lines and capitals are refrains.
A
B
a
A
a
b
A
B
My inspiration was the song Walk Away by Matt Monro (1965) It's on youtube.