180

180 is a number that represents a full rotation or revolution around a point. It is equivalent to half of a circle or a semicircle, and it is also equal to 180 degrees in the context of angular measurement. The number 180 is significant in various fields, including mathematics, geometry, and navigation.

In mathematics, 180 is a composite number, meaning it has factors other than 1 and itself. Its prime factors are 2, 2, 3, and 5. It is also an even number and a perfect square, as it can be expressed as 12^2.

In geometry, a 180-degree angle is known as a straight angle. It forms a straight line and is the angle between two rays that lie on the same line but point in opposite directions. A polygon with an interior angle of 180 degrees is known as a degenerate polygon, as it does not enclose any area.

In navigation, 180 degrees is used to indicate the opposite direction. For example, if a ship is traveling due north, a course of 180 degrees would mean the ship is traveling due south.

The number 180 also has cultural and historical significance. For instance, the year 180 is often associated with the Roman numeral C, which stands for 100. Additionally, the number 180 is used in various sports, such as basketball, where a shot made from behind the three-point line is worth 180 points in some scoring systems.