Complete each of the following, so as to make a true statement:
(i) A quadrilateral has ____ sides.
(ii) A quadrilateral has ____angles.
(iii) A quadrilateral has ____, no three of which are ____.
(iv) A quadrilateral has ____diagonals.
(v) The number of pairs of adjacent angles of a quadrilateral is ____.
(vi) The number of pairs of opposite angles of a quadrilateral is ____.
(vii) The sum of the angles of a quadrilateral is ____.
(viii) A diagonal of a quadrilateral is a line segment that joins two ____ vertices of the quadrilateral.
(ix) The sum of the angles of a quadrilateral is ____ right angles.
(x) The measure of each angle of a convex quadrilateral is ____ 180°.
(xi) In a quadrilateral the point of intersection of the diagonals **** in ____ of the quadrilateral.
(xii) A point is in the interior of a convex quadrilateral, if it is in the ____ of its two opposite angles.
(xiii) A quadrilateral is convex if for each side, the remaining ____ lie on the same side of the line containing the side.