You can put this solution on YOUR website!
Depends. Do you need the Lateral Surface Area or the Total Surface Area? The difference is that one includes the area of the base and one does not.
The base is nothing more than a circle of radius that is one-half of the given diameter.
The Lateral Surface area is found by multiplying times the radius times the slant height. The Total Surface Area is the Lateral Surface Area plus the area of the base,