In a parallelogram, the diagonals bisect each other. This means that the point where the diagonals intersect (point A in your case) splits each diagonal into two equal segments.
Given that WY measures 7 centimeters, point A will divide WY into two equal parts. Therefore, the length of AW is half of WY.
So, to find AW:
\[ AW = \frac{WY}{2} = \frac{7 \text{ cm}}{2} = 3.5 \text{ cm} \]
Thus, the length of AW is 3.5 cm.