Mathematical Enigma - XIV

If we have the four sides of a quadrilateral ,it's the cyclic quadrilateral which has the maximum area.We have sides of the quadrilateral as 1,2,3,4.Area of a cyclic quadrilateral is given by The Brahmagupta's Formula where $s=\dfrac {a+b+c+d}{2}$ .By this we have maximum area = $\sqrt{4×3×2×1}=2\sqrt {6} \approx 4.898.$

√((s-a)(s-b)(s-c)(s-d)) So the answer is 2√6