Three identical square sheets of paper each with side length 6 are stacked on top of each other. The middle sheet is rotated clockwise 30^{\circ} about its center and the top sheet is rotated clockwise 60^{\circ} about its center, resulting in the 24 -sided polygon shown in the figure below. The area of this polygon can be expressed in the form a-b \sqrt{c}, where a, b, and c are positive integers, and c is not divisible by the square of any prime. What is a+b+c ?
Answer Choices
A. 75
B. 93
C. 96
D. 129
E. 147
