My goal is to find the area of a segment BGC. Let's get started.
AJ = sqrt(AK2 - JK2) = 30√3
AH = 2/3(AJ) = 20√3
AE = HJ = 1/3(AJ) = 10√3
Angle BAC = 2[arccos(AB / AE)] = 109.4712206º
Area of sector ABGC = 302pi * (∠BAC / 360) = 859.784956 u2
Area of triangle ABC = BE * AE = 424.2640687 u2
Area of segment BGC = [ABGC] - [ABC] = 435.5208873 u2
Area of circle H = 302pi = 2827.433388
and finally...
Shaded area = 2827.433388 - (6 * 435.5208873) = 214.3080644 u2