The area of segment is given as Area of sector -area of triangle
Area of sector is 120360×π×62=12π
Area of triangle is 12×6×6×sin12012×36×√32=9√3
The area of segment is 12π−9√3
The area of shaded portion is given as area of hexagon - area of triangle.
Area of hexagon is 3√3a23√3×62108√3
Area of shaded region is 108√3−9√3=99√3