jmc

Let the common difference of this arithmetic sequence be $d$, so the second largest angle is $129-d$ degrees, the third largest is $129-2d$ degrees, and the smallest angle is $129-3d$ degrees. We know that the sum of the interior angles in a quadrilateral is equal to 360 degrees, so we have the equation $129+(129-d)+(129-2d)+(129-3d)=360$, from which we find that $d=26$ degrees. Thus, the second largest angle is $129-d=129-26=\boxed{103}$ degrees.