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.
Who are Environmental Engineers and What They do. Environmental engineers are specialists who study and perform environmental engineering. To this end, they take doctrines of engineering, science, biology and chemistry to formulate solutions to public health issues and environmental problems. Essentially, they study the effects technology has on the environment.