A real world example of a cubic function might be the change in volume of a cube or sphere, depending on the change in the dimensions of a side or radius, respectively.
A fjord is a real world example of a fjord! They exist in the real world.
The Equator is a real world example, being the circumference of the Earth.
Solid objects exist in real life. Each one of them has a surface area as well as a volume.
a shoebox with a lenght of 10 inches a width of 8 and a height of 4
Of what?
For example: Some products are sold by volume. Some appliances specify how much volume they have, since it affects their usefulness - for example, hot water bottles, or refrigerators. The capacity of a car or motorcycle is often specified in volume (of the pistons). While this is not a unit of power, larger pistons do tend to correspond to more power.
For example, many liquids are sold by volume (such as, "please sell me a liter of milk").
where could you find a pentagon in the real world
Example is too omitted to be real. Example is much more unresponsive
2 is a real world prime number.
a example of a hendecagon is a hedecagon