Looking at the attachment, we'll determine entire hexagon area with this formula:
area = apothem^2 *Number of sides * tan(180/n)
area = 17.32^2 * 6 * tan (30)
area =
299.9824
* 6 * 0.57735
area =
1,039.16903184
Now we subtract the triangle area (16*20 = 320)
shaded area =
1,039.16903184
-320 =
719.16903184
answer is D