Polygons bcde & fghi are similar

                b) ∠H

                c) ∠E

Step-by-step explanation:

I find it easiest to do these problems if I write one polygon on top of the other.  That way I can easily see the angles and sides that match.

B C D E

F G H  I

a) BC matches to FG and FI matches to BE

   The proportion is:  

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b) What matches with ∠D? Look at the letter below to see that it is ∠H

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c) What matches with ∠I? Look at the letter above to see that it is ∠E

b.an increase in a causes b to decrease