Define the following terms:
(i) Quadrilateral (ii) Convex Quadrilateral.
(i) Quadrilateral: A closed figure made of four line segments is called a quadrilateral such that:
(a) no three points of them are collinear
(b) the line segments do not intersect except at their ends points.
(ii) Convex quadrilateral: A quadrilateral is called a convex quadrilateral of the line containing any side of the quadrilateral has the remaining vertices on the same side of it. In the figure. quadrilateral ABCD is a convex quadrilateral.