When two shapes are mathematically similar, that means that all their sides are in a proportion.
We know the sieds of EH and AD, and so we can find the proportion of the shapes using these two sides.
EH/AD = 6/9 = 2/3
The ratio of EFGH to ABCD is 2:3
Now we have to find BC.
Becuase they're in proportion, we can form this equation:
 =
 = 
Cross multiply:
24 = 2*BC
Divide both sides by 2:
BC = 12 cm
Good luck!
 
        
             
        
        
        
I can assure you that it is A
        
                    
             
        
        
        
Answer:
 
 
Step-by-step explanation:

 
        
             
        
        
        
Answer:
9(r + 8) = 9r +72
Step-by-step explanation:
9(r + 8)
9r + 72
Hope this helps!