U multiply the radicals then the total answer will be a radical
648 cm
To find the volume of a rectangular prism (such as the one in the picture) you would do:
V=L*W*H
So plugging the numbers in:
V=18*12*3
At 4200, the max tax is about 2,400 so to get to 3200 raise by 800 which is 1/3
so 1/3 of 4000
or do 16.66 times 3200 which gives u about 53333.33