Answer:
113.57 unit²
Explanation:
Surface area of a pyramid with regular hexagonal base 
= Area of slant sides + area of Hexagonal base
Area of one slant side = 
 (side of base) × slant height
 (side of base) × slant height
 = 
 × 6 × 4
 × 6 × 4
 = 3 × 4
 = 12 unit²
Since hexagonal pyramid has 6 slant sides.
So area of sic slant sides = 6 × 12 = 72 unit²
Now for the area of hexagonal base we will take triangle ABC.
∠BAC = 60° [angle formed at center = 
 ]
 ]
and ∠CAD = 30° 
Now tan 30° = 
 =
 = 


AD = 

Now hexagonal base area = 6 × [
 (BC)(AD)]
 (BC)(AD)]
6 × [
 ×
 × 
 ] =
] = 

Therefore area of the pyramid = 72 + 41.57 = 113.57 unit²