ΔABC is a right angled triangle, the radius of its circumcircle is 3 cm and the length of its altitude drawn from the opposite vertex to the hypotenuse is 2 cm. Then the area of the triangle is
A cylindrical vessel of radius 4 cm contains water . A solid sphere of radius 3 cm is dipped into the water until it is completely immersed . The water level in the vessel will rise by