Answer:
19.58 unit²
Step-by-step explanation:
To find the area of the shaded region, we use the formula:

As we know that,
= 
=36πunit²
Next is to split up the hexagon into 6 regular triangles.

=6 x 
the base is equal to the radius i.e 6 as the triangles are regular.The height can be represented by taking one of the triangles and drawing a line down the middle.
So, the newly formed triangle is a 30°-60°90° right triangle.
(see figure 1 in attachment)
Here, a= 6/2=> 3
h= a√3 => 3√3
Substituting the required values in the formula of area of hexagon, we get
=> 54√3unit²

=36π-54√3
= 19.58 unit²