But since it a hat, therefore, we will have to subtract the circular area because the hat is not completely covered with a circular part.
Here, the diameter is 4 inch and therefore, the radius is half of diameter that is r=2 inch and it is also given that slant height is thrice the radius that is l=(3×2)=6 inch. We use π=3.
Thus,
Area of hat=πr(r+l)−πr2=3×2(2+6)−3×2×2=3×2×8−12=36 in2.
Hence, the surface area of the conical hat is 36 in2.
Therefore, option B is correct.