Question 610711
To solve a rectangular prism (or a cube), you'd use the formula {{{v=l*w*h}}}. But in this case, we have dimensions that are not similar to each other. To make them similar, we'd have to choose a common measure. Let's convert everything to meters.

To convert 5cm to meters, you'd use this formula: {{{cm/100=m}}}. In this case, it'd be 5/100=.05 meters.
To convert 23km to meters, you'd use this formula:{{{km*1000=m}}}. In this case, it'd be 23*1000=23,000 meters.
345 meters is already in meters, so we don't have to convert that.

Now, you'd plug those into the rectangular prism formula to get: .05*345*23000=396,750 meters in total.