There is no picture in your questin
8000.hope this help if not tell me please.
The cross-section of a sphere is a circle . The area of a circle can be calculated by the formula A=
Where r is the radius of the circle.
Given :
Solving for r we have:

Or r= 10.
The area of a sphere is calculated by the formula :

Substituting r value we have:
SA= 
The total surface area of this sphere is 400π .