This is a regular hexagone. If you draw each vertex to the center, it will be divided into r equilateral triangle. Since each side = 8 mm, the central diagonal is equal to 16 mm (Diameter of the subscribed circle).
Area of the shaded trapezoid = (B+b),H/2
B= 16 mm
b= 8.6 mm
H = 2.8 mm
Area = [(16 + 8.6).2.8]/2 = (24.6)(1.4) = 34.44 mm²
