Area

Area Country Subdivision

Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in a plane.

The simplest area for a figure is the rectangle (length x width)

A = lw (rectangle)

A = s2 (square)

A = 1/2 X b X h (triangle)

A = πr2 (circle)

A = 4πr2 (sphere)

Archimedes showed that the surface area of a sphere is exactly four times the area of a flat disk of the same radius, and the volume enclosed by the sphere is exactly 2/3 of the volume of a cylinder of the same height and radius.

See also …
en.wikipedia.org/wiki/Area