ABCD be the rectangle inscribed in the circle of diameter 5cm.
∴ Diameter = Diagonal of rectangle Now, let x and y be the lengths and breadths of rectangle, respectively. Now in ΔABD, AB2+AD2=(5)2⇒x2+y2=25 Since, they form Pythagoras triplet, ∴ x=4 and y=3 So, area of rectangle =3×4=12cm2