Find the reference angle for a rotation of $249^{\circ}$.

Step 1 ：The given angle is 249 degrees.

Step 2 ：Since 249 degrees is in the third quadrant (between 180 and 270 degrees), we can find the reference angle by subtracting 180 from 249.

Step 3 ：Using the formula for the reference angle in the third quadrant, \(angle - 180\), we substitute 249 for the angle.

Step 4 ：\(reference\_angle = 249 - 180\)

Step 5 ：\(reference\_angle = 69\)

Step 6 ：Final Answer: The reference angle for a rotation of 249 degrees is \(\boxed{69^{\circ}}\)