What is a prism? A prism is a three dimensional figure with parallel bases.
The formula for finding the volume of a prism is just length X width X height
Let’s look at a problem
What is the volume of a prism with a base of 6 by 7 units and a height of 9 units?
Step 1 Plug the units into the formula l * w * h 6*7*9
Step 2. Multiply 6*7*9 = 42*9
42*9 = 378 units cubed (volume is always cubed)
Now a prism can be have different shaped bases. The key to finding the volume is to find the base area formula for that shape and then multiply this by the height.
Check here for a list of most base area formulas
For example, if you had a triangle shaped prism you would use ½ base x length x height to find the volume of the triangular prism