Respuesta :

The cross-section of a sphere  is a circle . The  area of a circle can be calculated by the formula A= [tex] \pi\r^{2}   [/tex] Where r is the radius of the circle.

Given :[tex] \pir^{2}   = 100\pi   [/tex]

Solving for r we have:

[tex] r^{2} = \frac{100\pi }{\pi}=   100 [/tex]

Or r= 10.

The area of a sphere is calculated by the formula :

[tex] SA = 4\pi  R^{2}   [/tex]

Substituting r value we have:

SA= [tex] 4\pi\ 10 ^{2}    = 400\pi   [/tex]

The total surface area of this sphere is 400π .