Question

how can you categorise animals based on symmetry?

Answer 1

According to the body symmetry animals can be categorized into animals having radial or bilateral symmetry.
Some animals have radial or rotational symmetry, when the organism has body parts arranged around the central axis (for example, sea anemones). Subtype of radial symmetry is fivefold symmetry (starfish, sea urchins, and sea lilies).
Two-sided symmetry is called bilateral or mirror symmetry (for example human, tiger or dog).
Bilateral symmetry animals typically have a dorsal (top) side and a ventral (bottom) side; right and left side; anterior (head) and posterior (tail) ends