A trapezoid, after the lower sole is shortened by 11.1 cm, just becomes a square. The perimeter of the square is 35.6 cm, and the original trapezoid area is ()

A trapezoid, after the lower sole is shortened by 11.1 cm, just becomes a square. The perimeter of the square is 35.6 cm, and the original trapezoid area is ()

35.6÷4=8.9
8.9+11.1=20
(8.9+11.1)×8.9÷2=89