What was an immediate effect of the completion of the erie canal in 1825?

There are actually three immediate effects of the completion of the Erie Canal in 1825 and these are the following: 
1. There was an increase for food product prices along the Atlantic Coast.
2. A territorial conflict began with Canada over the Great Lakes.
3. It made farmers to more easily ship grain to eastern markets. 
Hope this is the answer that you are looking for. 

Use the formula: (n-2)×180, where n is the number of sides(18-2)×180= 28800, now this is the full exterior angle of 18-gon so you divide it by 18.28800÷18=160