Formula for the volume of a cone = 1/3h(pi)r^2
1.5(which is r or the radius) squared is equal to 2.25.
Multiply by the height (9) and you get 20.25.
Multiply by 1/3, and get 6.75.
Finally, multiply 6.75 with pi.
6.75pi is equal to the volume of one cone.
Then, multiply by 6.
40.5in^2