Question 3181
 For any polygon with n sides, the total interior angles =
 180(n-2) = 540 when n=5.

 Assume the middle angle is x, the five angles are x-2,x-1,x,x+1.x+2
 we have the sum of them is 5x.
 
 Solve 5x =540, 
 so x = 108 and the largest angle is 108+2 =110 deg

 Kenny