puolisuorat

Puolisuorat are a fundamental concept in geometry, representing a ray that extends infinitely in one direction from a starting point. Unlike a line segment, which has two endpoints, or a line, which extends infinitely in both directions, a puolisuora has a single, defined beginning. This starting point is often referred to as the vertex or endpoint of the puolisuora.

In geometric notation, a puolisuora is typically denoted by its starting point followed by another point that lies on the ray. For instance, a puolisuora starting at point A and passing through point B would be written as AB with a small arrow above the letters, indicating the direction of extension. The ray is considered to include its starting point.

Puolisuorat are essential for constructing various geometric figures and understanding angles. An angle, for example, is formed by two puolisuorat that share a common starting point, the vertex. The concept also appears in coordinate geometry, where puolisuorat can define regions or boundaries within a plane. The directionality of a puolisuora is a key characteristic, distinguishing it from other geometric entities. They are a building block for more complex geometric ideas and proofs.