1. By folding a polygonal paper, a line segment can be drawn on the paper and the paper can be folded along it. As shown in Figure 1, for the given shape on the paper, cutting along the boundary of the shaded part will yield a polygonal paper. For this polygonal paper, a rectangular paper can be obtained with at most five folds. Please draw the crease lines and the shape of the paper after each fold on the answer sheet to describe your method.
Note: The crease lines do not necessarily have to coincide with the grid lines on the shape.
1. There are different ways to fold the given paper into a rectangle according to the problem requirements. As shown in Figure 3 (a～d), the folding methods are given in sequence, requiring only 4 folds.

Note, in the third and fourth folds, the crease lines can be slightly moved up or down, and all crease lines must be within the figure.