The radius around a particular point is the distance from it in any direction.
long radius
the distance from the centre of a regular polygon to a vertex
short radius
the perpendicular distance from the centre of a regular polygon to a side
turning radius
the smallest circle in which a vehicle can turn
cruising radius
the greatest distance that an aircraft or ship can cruise , away from and back to a certain point without refueling
radius vector
a line joining a point in space to the origin of polar or spherical coordinates
Schwarzschild radius
the radius of a sphere ( Schwarzschild sphere ) surrounding a non-rotating uncharged black hole , from within which no information can escape because of gravitational forces