Vector which is perpendicular to said surface or manifold. In a inner product space, the inner product of the normal vector with all vectors which comprise the surface is 0.
... 2000, there are 19,701 people, 6,700 households, and 5,011 families residing in the town. The population density is 1,549.2/km² (4,010.1/mi²). There are 6,949 ...