The diameter of the pile is $\"\"$ .

The radius of the conic is $\"\"$ .

Substitute $\"\"$ in $\"\"$ .

$\"\"$

$\"\"$ .

The slant height is $\"\"$ .

Find the surface area of the conical pile exposed to the air.

Surface area of the conic $\"\"$ .

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

$\"\"$ .

The surface area of the conical pile exposed to the air is $\"\"$ .