Puolisuora

Puolisuora is a geometric term that describes a ray in Euclidean geometry. It is a part of a straight line that starts at a particular point and extends infinitely in one direction. The starting point is called the endpoint or origin of the puolisuora.

A puolisuora can be defined by two points: its endpoint and another point that lies on the puolisuora. The endpoint determines the direction of the ray. For example, if a puolisuora starts at point A and passes through point B, it is denoted as $\vec{AB}$. This indicates that the ray begins at A and extends indefinitely through B.

In contrast to a line segment, which has two finite endpoints, a puolisuora has only one endpoint and extends infinitely in one direction. Unlike a line, which extends infinitely in both directions, a puolisuora is restricted to a single direction from its starting point.

Puolisuorat are fundamental concepts in geometry and are used in various areas, including trigonometry, vector analysis, and the study of angles. An angle, for instance, can be formed by two puolisuorat that share a common endpoint. The region between these two rays, measured from a starting ray to a terminating ray, defines the angle. The concept of a puolisuora is essential for understanding more complex geometric shapes and relationships.