Question

what is Triple integration ?

Answer 1

Double integrals and triple integrals are used to find volumes of 3D objects. The best way to think of it is to think of it as if you are doing it layer by layer like a 3D printer would create an object. Each layer has an area and if you stack the layers, you get a 3D solid.

Answer 2

Another example I like to consider is imagine you want to find the total heat inside your rectangular room. Well at each point in your room there's a temperature, and it might not be consistent, for instance there might be a heater in the corner causing the temperature to be warmer at one place rather than another. So what we can do to find the total heat in your room, or in a block of steel, or whatever, is we take the temperature function and integrate (add it up) over the entire object and that tells us the total heat content.