讲解一下这道题---乙部：解答题 (共三题, 每题 20 分, 共 60 分。必须写出详细解答过程或步骤) 1. 如图, ABCD 是正方形。H 是 AD 的中点, G 是 CD 的中点, E、F 在线段 AB、BC 上, 且 AE = 3, BF = 2。四边形 EFGH 的面积 = 53, 则 AB = ? Chart/Diagram Description: * Type: Geometric figure. * Main Elements: * A square ABCD is shown. The vertices are labeled counter-clockwise starting from A at the top right, B at the bottom right, C at the bottom left, and D at the top left. * Point H is on segment AD, appearing to be the midpoint. * Point G is on segment CD, appearing to be the midpoint. * Point E is on segment AB. The value '3' is labeled near E, suggesting the length of AE. * Point F is on segment BC. The value '2' is labeled near F, suggesting the length of BF. * A shaded quadrilateral EFGH is formed by connecting these points. * The number '53' is written inside the shaded quadrilateral, representing its area.