A sheet of paper
Two rubber band
Take the sheet of paper and roll it into a tube.
Tie both the ends of the paper tube with rubber bands and make it stand upright on a flat surface.
Now, place a book on the top of the tube. You will see that the paper tube supports the weight of the book.
How does this work?
The tube is known to have more strength than a flat object. Hence, it is strong enough to hold the weight of another object. Pillars, therefore, are great examples. Since they have a shape of a tube, they can hold the weight of buildings.