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.
1 This type of screw is still used today to pump liquids. 2  Other machines. 3  Archimedes designed a pulley system that helped sailors lift objects that were too heavy to move by hand. 4  He is also said to have improved the catapult and invented the odometer, a device that measures the distance traveled.