The smallest of these, 
  
    
      
        
          
            
              g
            
          
          
            2
          
        
      
    
    {\displaystyle {\mathfrak {g}}_{2}}
  , can be represented in five-dimensional complex space and projected in the same number of dimensions as a ball rolling on top of another ball, whose motion is described in two-dimensional space.
Its 
  
    
      
        3
      
    
    {\displaystyle 3}
   x 
  
    
      
        3
      
    
    {\displaystyle 3}
   array of squares has a magic constant 
  
    
      
        M
      
    
    {\displaystyle M}
   of 
  
    
      
        15
      
    
    {\displaystyle 15}
  , where the sums of its rows, columns, and diagonals are all equal to fifteen. 5 is also the value of the central cell the only non-trivial order-3 normal magic hexagon that is made of nineteen cells.Polynomial equations of degree 4 and below can be solved with radicals, while quintic equations of degree 5, and higher, cannot generally be so solved. This is the Abel–Ruffini theorem.