Question

My legs are pillars which figure of speech

Answer 1

Metophor

its a comparitive figure of speech
here you are are comparing your legs to the pillar
any other sentence which compore some living thing with something else is a metophor
examples:
Her hair is as silky as velvet
Are eyes are as bright as diamonds



hope it helps 
for further doubts feel free to ask

courtesy fire furry

Answer 2

Exaggeration and metaphor Is the figure of speech