- United States Secretary of Homeland Security (Wikipedia)
The United States secretary of homeland security is the head of the United States Department of Homeland Security, the federal department tasked with ensuring public safety in the United States. The secretary is a member of the Cabinet of the United States. The position was created by the Homeland Security Act following the attacks of September 11, 2001.
- Radius (Wikipedia)
In classical geometry, a radius (pl.: radii or radiuses) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the Latin radius, meaning ray but also the spoke of a chariot wheel. The typical abbreviation and mathematical variable name for radius is R or r. By extension, the diameter D is defined as twice the radius
