.
As the problem is worded, I assume, based on the context, that the question is about the area
of the horizontal cross-section of the concrete wall, and not about the area of the wall itself.
With enough precision, the area of the horizontal cross-section is the product of the circumference
by the wall thickness, both expressed in centimeters
the area of the horizontal cross-section = 
= 
= 62857 cm^2. ANSWER
Solved. // Notice that 22/7 is a rational approximation for 
.
