To correctly compare \( \pi^2 \) and 9, we first consider the value of \( \pi \). The numerical value of \( \pi \) is approximately 3.14159. Since this value is greater than 3, we can use the following reasoning:
- Since \( \pi > 3 \), we can square both sides: \[ \pi^2 > 3^2 \] \[ \pi^2 > 9 \]
From this, we can conclude that \( \pi^2 > 9 \).
Therefore, the correct statement is:
D. \( \pi > 3 \), so \( \pi^2 > 9 \).