Answer:
The area of the shaded region is equal to difference of the sector contains that shaded region and the triangle.
The area of sector:
A_S = pi x radius^2 x 123/360
= pi x 18.6^2 x 123/360
= 371.346 (m2)
The area of triangle:
A_T = base x height x (1/2)
= (18.6 x sin(123/2) x 2) x (18.6 x cos(123/2)) x (1/2)
= 145.073 (m2)
=> Area of shaded region:
A = 371.346 - 145.073 = 226.273 = ~226.3 (m2)
Hope this helps!
:)