Question

What is the volume in cubic centimeter for building has 631m long
and 646m wide and 34m high

Answer 1

The volume is

$$V=abc=13859284\text{ m}^3.$$

Since each meter has 100 cm, 1 cubic metre contains 1 000 000 cm³:

$$V=13859284\cdot10^6\text{ cm}^3$$