They support their on weight.
The shape and what it is made of.
Anthony Wotherspoon makes a good structure. hes strong and sturdy. Anthony Wotherspoon makes a good structure. hes strong and sturdy.
It's arches.
bones
Steel and geometry, tension, straight, aches and channels make a good bridge
The present London Bridge is a pre-stressed concrete box girder bridge which makes it very strong.
The supports that are under the bridge is very thick and strong which makes londen bridge strong.
It's chemical structure that prevents movement of electrons.
While the material is semi important, what makes a bookcase or any structure strong is the build. With that being said, a consumer would want a bookcase made out of wood or something stronger like a metal.
the top material is wood. wood is strong, flexible, and easy too carve.
Element
Arches-Spreads the weight throughout the structureBeams-Support structure for a lot of weightTriangles- Strongest shapeSymmetry- Same on both sides
Iron is really strong and there fore makes a good substance to use.