Question: how do you work out the surface area of a hemisphere?
Answer: If you have a hemispherical object then it has a base which is a circle of radius r. The area of a circle of radius r is π r2 and thus if the hemisphere is meant to include the base then the surface area is 2 π r2 + π r2 = 3 π r2. Hence in this case 3 π r2 = 1062. Solve for r.