Question 634647
The formula for the sum of the interior angles of the formula is {{{sum=180(n-2)}}}. In this case, we know the sum instead of the sides. Let's plug that in: {{{3060=180(n-2)}}}. 
<p>Now, we have to isolate the variable. Start by dividing out the 180. {{{17=n-2}}}. Then, add 2 to both sides to take out the -2. {{{15=n}}}
<p>So, the polygon has <b>15 sides.</b> I hope this helps!