Answer: 
 The radius is: 
Step-by-step explanation:
 The equation of a circle in center-radius form is:
 
 Where the center is at the point (h, k) and the radius is "r".
 So, given the equation of the circle:
 
 You can identify that:
 
 Then, solving for "r", you get that the radius of this circle is:
 
 
        
                    
             
        
        
        
A radioactive atmosphere around the area and an expensive, hard time cleaning everything up.
 
        
             
        
        
        
7x4x100=2800
7x4x1000=28,000