**The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep.**
This tercet is from Robert Frost's famous poem "Stopping by Woods on a Snowy Evening". Notice how the rhyme scheme is AAB, with the second and third lines rhyming.
Here's another example:
**The sun dips low, a fiery hue,
The clouds ablaze, a crimson view,
A final kiss before the night is due.**
This tercet uses a different rhyme scheme (AAA), with all three lines rhyming.
Let me know if you'd like to see more examples or have any other questions!