This function for checking point inside polygon or not By using IRelationalOperator2.
public bool chkPointInSide(IPoint pPnt, IFeature pFeature)
{
bool flg = false;
try
{
IRelationalOperator2 pRel = pFeature.Shape as IRelationalOperator2;
flg = pRel.Contains(pPnt);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
return flg;
}