Quadrilateral. In Euclidean plane geometry, a quadrilateral is a polygon with four sides (or 'edges') and four vertices or corners. Sometimes, the term quadrangle is used, by analogy with triangle, and sometimes tetragon for consistency with pentagon (5-sided), hexagon (6-sided) and so on.
Some environmental scientists and specialists focus on environmental regulations that are designed to protect peopleâs health, while others focus on regulations designed to minimize societyâs impact on the ecosystem.
: This scientist studies animals living in the wild, including what they eat, their habitat, and how they interact with their environment. Wildlife ecologist. : This kind of scientist studies the relationship of different kinds of wildlife with each. other and with their living and nonliving environment.