Хватит ли изгороди длиной 40 м для участка квадратной формы с длиной стороны 80 дм?

1) Many thousands of years ago there were no houses such as peo­ple live in
today, weren't there?

2) Did later people leave their caves and trees and begin to build houses out of different materials such as mud, wood or stones?

3) Did the ancient Egyptians or Chineses often erected their huge constructions to commemorate their kings or pharaohs?

4) Who understood the art of building with cut stone, and their buildings were beautiful as well as useful?

5) What did they also erect?

6)  Some of their constructions are used till now, aren't they?

7) Is it known that the manufacture of lime is one of the oldest industries used by
man?