To find \( f(6) \) using the function rule \( f(x) = (x - 12)^2 \), you need to substitute \( x \) with \( 6 \).
So,
\[ f(6) = (6 - 12)^2 \]
Now, calculate the expression inside the parentheses:
\[ 6 - 12 = -6 \]
Next, square the result:
\[ (-6)^2 = 36 \]
Thus,
\[ f(6) = 36 \]
Therefore, the answer is \( f(6) = 36 \).