Answer:
go to a called math and  way but without  the space or the and
Step-by-step explanation:
 
        
                    
             
        
        
        
Okay so make a coordinate plane, insert the numbers in the right place, then count what’s in between, you got this, I’ll totally help you if you didn’t get it.
        
             
        
        
        
Answer:1385.44mm sq
Step-by-step explanation: surface area of a circle = pi x radius squared 
3.142 x 21 squared