Symmetry: Similarity of form or arrangement on either side of a dividing line or plane.
Beam: A horizontal building element.
Column: A vertical building element.
Joint: A place or part where two things or parts are joined.
Dead Load: The weight of a structure itself.
Live Load: The weight of anything on a structure.
Gravity: On earth it is a vertical or downward force that is acting on everything including the towers being built by students. This force pulls all objects on the earth’s sphere toward the center of the earth.
Center of Gravity: The spot at which the mass of an object seems to be concentrated and weight is being pulled directly down on by gravity. It is also the balance point for an object.
Stability: The capacity of an object to return to equilibrium or to its original position after having been displaced by some force. For an object to be stable and remain upright its center of gravity must be above its base. As the center of gravity is moved away from the center of its base then it becomes less stable and easier to tip over. When the center of gravity is no longer located above the base then the structure cannot stand upright. A center of gravity that is low and close to the base also makes a structure very stable.
Compression: The stress/force felt when an object is being pushed together (inward).
Tension: The stress/force felt when an object is being pulled apart (outward).