Let ABCD be a cyclic quadrilateral with sides AB = 2 cm, BC = 7 cm, CD = 11 cm, DA = 14 cm. Find the product of its diagonals.
Let ABCD be a quadrilateral with diagonals AC and BD. Prove the following statements (Compare these with the previous problem);
(a) AB + BC + CD > AD;
(b) AB + BC + CD + DA > 2AC;
(c) AB + BC + CD + DA > 2BD;
(d) AB + BC + CD + DA > AC + BD.