Answer:
The given lines are a metaphor.
Step-by-step explanation:
The lines "I'll be the roots, and you'll be the tree" are from famed singer Beyonce's "Black Is King" film. This hour-long film revolves around the acceptance of one's identity, especially in black people. Loosely following along the storyline of "The Lion King," this film revolves around a young black prince who is about to pave his way into the world.
Figurative languages are those languages used to describe or give 'color' to the scenes in the book/ story. Writers employ various techniques such as metaphors, alliteration, simile, oxymoron, etc. to achieve such effects. The figurative language in the given lines is a metaphor.
Metaphors are used to make comparisons between unrelated things and which cannot be literally taken as reality. But it does give a sense of understanding and makes a picture clearer. So, with the metaphor "I'll be the roots, you'll be the tree", the comparison is with a tree that stands firm for the branches to spread their arms full and free.