The trapezoid is isosceles, as indicated by the hash marks on sides AD and BC. This means it is symmetrical about the vertical center-line. Angles on the right will have the same measures as the symmetrical angles on the left.
So, you know immediately that ∠B = ∠A = 53°.
Because AB ║ DC, ∠A and ∠D are supplementary. That is, ...
