Answer:
area = 1539√3 in²
Explanation:
three hexagons and one triangle:
each of the three hexagons are composed of 6 equilateral triangles just like the center triangle.
So you have 19 equilateral triangles with each side being 18 inches long.
The height (h) of a triangle will be:
h² = 18² - 9² = 324 - 81 = 243
h = √243
h = 9√3
area of one triangle = 1/2bh = (1/2)(18)(9√3) = 81√3
81√3(19 triangles) = 1539√3 in²