Which term describes two sides that are symmetrical?

The term that accurately describes two sides that are symmetrical is bilateral symmetry. This concept refers to a characteristic where the left and right sides of an organism or object mirror each other in form and structure. It is a foundational principle in various fields including biology, art, and anatomy, indicating balance and proportionality. In animals, bilateral symmetry allows for organized body plans with paired structures, such as limbs or eyes, enhancing movement and other functions.

The other terms represent different concepts: medial refers to a position closer to the midline of the body, unilateral describes something occurring on one side only, and contralateral indicates structures or actions involving opposite sides. Each of these terms applies to specific contexts but does not convey the idea of both sides being symmetrical like bilateral symmetry does.