Angles of a quadrilateral add up to 360. We are already given 69 and 45, which can both be subtracted from 360, leaving us with 246. Since the two remaining angles are congruent, 246 can be divided by 2 to find the remaining measure(s). We are left with 123. However, m<ADE is supplementary to this. So we subtract 123 from 180. The final answer is 57 degrees.
