The area of a square quilt and its side length, is the relationship linear?

Área=side^2 hope this helps :-)

Area=side^2

if we say area=y and side=x

y=x^2

an euation is linear if the highest power of the variables is 1
y^1=x^2
2≠1
it is not linear (it's quadratic, fancy term for 2nd degree)

Bruh sound effect #2