16.1  
 
16.2  
16.4  
 
 
16.1.1 
 
  
 
     
 
16.3 
    
 
16.5 
16.6.1 
    
 
16.6 
16.6.2 
 A small wheel rolls around a large fixed wheel without slipping.  
 What path does a point on the edge of the small wheel trace out as it goes?