Since \( P \) and \( Q \) are midpoints,
\[
AQ = \frac{1}{2} AB, \quad PQ = \frac{1}{2} BC
\]
Applying the midpoint theorem:
\[
4AQ^2 = AB^2 + 4PQ^2
\]
Since \( AB^2 = AC^2 + BC^2 \) (Pythagoras theorem),
\[
4AQ^2 = 4AC^2 + BC^2
\]
Thus, the given equation is proved.
Correct Answer: \( 4AQ^2 = 4AC^2 + BC^2 \) is proved.