To find the circumference of a circle, you can use the formula:
\[ C = \pi \times d \]
where \(C\) is the circumference and \(d\) is the diameter.
Given the diameter \(d = 15\) cm and using \( \pi \approx 3.14\):
\[ C = 3.14 \times 15 \]
Calculating that:
\[ C = 3.14 \times 15 = 47.1 , \text{cm} \]
Therefore, the circumference of the window is 47.1 cm.