You've been working with rectangular prisms all night, and the same formula gives the volume of every one of them. Unfortunately, you used way more time asking other people for answers than it would take you to solve them on your own.
The formula is:
Volume = (length) times (width) times (height) .
With that formula, you can directly solve problems #1, #2, #3, #4, and #8. It's also the only math you really need to solve #9 ... but you also need to use your brain cells for #9.
For #6, start with the same formula:
Volume = (length) x (width) x (height)
Divide each side by (width) x (height), and then it says: Length = (volume) / (width x height) .
#6 gives you the volume, width and height. You can just write them into this equation, and bada-bing, you'll have the missing length.
ΔADB ≅ ΔCDB By Side-Side-Side (SSS) rule of congruency
ΔADB = ΔCDB By the definition of congruency
If the three sides of one triangle are congruent to the corresponding three sides of another triangle, then both triangles are said to be congruent according to the SSS rule of congruency