which is the biconditional of the following statement: if a polygon is a triangle, then it has exactly three sides. responses a polygon is a triangle if and only if it has exactly three sides. a polygon is a triangle if and only if it has exactly three sides. if a polygon does not have exactly three sides, then it is not a triangle. if a polygon does not have exactly three sides, then it is not a triangle. if a polygon has exactly three sides, then it is a triangle. if a polygon has exactly three sides, then it is a triangle. a polygon is not a triangle if and only if it does not have three sides