Let
AH---------------------> area of the regular hexagon
we know that
AH is equal to 6 areas of equilateral triangles (A):
AH = 6A
A= √3 * r²/4 (area of equilateral triangle)
r=20 in
then
A=√3 * 20²/4=100√3 in²
AH = 6*[100√3]=1039.23 in²
the answer is 1039.23 in²