Find the area of a rhombus if its vertices are (3, 0), (4, 5), (– 1, 4) and (– 2, – 1) taken inorder. [Hint: Area of a rhombus
(product of its diagonals)]
Let (3, 0), (4, 5), ( - 1, 4) and ( - 2, - 1) are the vertices A, B, C, D of a rhombus ABCD

Length of diagonal AC = [(3 + 1)2 + (0 – 4)2]1/2
= ![]()
= ![]()
Length of diagonal BD = [(4 + 2)2 + (5+ 1)2]1/2
= ![]()
= 6![]()
Therefore,
Area of rhombus ABCD =
*
* 6![]()
= 24 square units