I have 4 questions I need to verify if I calculated correctly for a project I have

Question

anonymous · Answer

the first 2 are for 2 rectanguler prisms I am trying to find the volume
 for

anonymous · Answer

First Prism i H=10 inches W=2 inches not sure how to find the lengh as the formula to calculate volume =l*w*h

anonymous · Answer

2nd question is similer but I need to find the volume for paper H=8 inches and W=2.5 inches same formula but not sure how to find the length

anonymous · Answer

3rd question I need to find the volume for 2 cylinders
radius will be 1.25 and the height will be 8 inches

4th question is-the radius will be 1.6 and the height will be 10 inches

the formula to calculate is-is V=pi r2 * h

anonymous · Answer

I am having trouble with the sqrt of the calculater