s=r*theta where s is arc length and the r is radius and theta is in RADIANS ONLY!! If you use degrees this formula does not work.
So we have a arc length of 38.485ft and a radius of 7. So rearranging the formula for theta, we get;
theta=(38.485)/(7)= 5.498radians then to convert to degrees if needed just take;
5.498rad*(180/pi)= 315deg