Answer:
3) 40 decimeters = 4 metres
7) >
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Uhh could you please include a image or something to help someone know it more Cleary with what you need help with
        
             
        
        
        
B: 78.50
If you plug in 5 for r, then you get  3.14 * 25, which is equal to 78.5 
Hope this helps!