The expression \( A = 8^2 \) simplifies to \( A = 64 \), which is a constant value. A linear equation is typically in the form \( y = mx + b \), where \( m \) is the slope and \( b \) is the y-intercept. Since \( A \) does not vary with a variable—instead, it is just a constant—this expression is not linear or non-linear in the traditional sense used for variable relationships.
If you are asking whether the equation \( A = x^2 \) (with \( A \) expressed as a function of a variable \( x \)) is linear or non-linear, the answer would be that it is non-linear due to the exponent on \( x \).