A "Hemi" or "Hemispherical" refers to half of a sphere. This shape is commonly seen in various fields, including architecture, engineering, and design. For example, a dome can be described as a hemispherical structure, providing both aesthetic appeal and structural integrity. In mathematics, the term is often used to describe the properties of a hemisphere, which is the three-dimensional counterpart of a circle. The surface area and volume of a hemisphere can be calculated using specific formulas, making it a fundamental concept in geometry and related disciplines like physics and engineering.