1, at △ABC, ∠ ACB = 90, AC = BC = 10, at △DCE, ∠ DCE = 90, DC = EC = 6°, point D is on the line segment AC, and point E is on the extension line segment BC.

2. If C is a moving point outside the fixed line segment AB, make a square CADF and a square CBEG with AC and BC as sides, and prove that the midpoint M of the line segment de is a fixed point on the same side of the straight line AB, no matter how the position of C changes.