In geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, or right angles).[1] It can also be defined as a rectangle in which two adjacent sides have equal length. A square with vertices ABCD would be denoted â» {\displaystyle \square } ABCD.
Ever since they were invented, catapults have been a deadly war weapon. The catapult was invented by Dionysius of Syracuse around 400 B.C. In Greek, the word catapult means to throw into. When he designed the catapult, Dionysius wanted to create an effective war weapon. The first catapult designed worked like a crossbow. To be able to make the catapult more powerful, it was made larger and stronger and set on a tripod.
A catapult is a type of machine used as a weapon to throw rocks or other things such as hot tar, that would cause damage to something else. Often, catapults were set on higher ground or on castle towers to let them shoot farther. They shot rocks to break castle walls, or pitch or hot tar to set the target on fire. Catapults use weights and levers to send the rocks or other things into the air. They do not throw as far as modern weapons do, and are not useful in modern warfare. Catapults were common in the past, especially the Middle Ages. Nowadays catapults are used to study old weapons, and as experiments (for example in physics or engineering classes).