# Area

**Area** is the amount of space a two dimensional (flat) surface takes up. It is useful because it is how much of a material is needed to make a hollow container. Area is the amount of surface covered by a close object or shape.

Some units used to measure area are square foot, square mile, square metre and square kilometre. The area of a planar figure is often written as [math]\displaystyle{ A }[/math].^{[1]} Areas of regular shapes such as square, rectangle, triangle and circle can be calculated through formulas.^{[2]} The area of an irregular shape can be approximated through grid or graph paper.^{[3]}

One can use different formulas to find the area of different shapes. For example:^{[2]}

- Area of a rectangle is the length of any two touching sides multiplied together. In other words, length times width.
- Area of a triangle is half of the base multiplied by the perpendicular height. In other words, [math]\displaystyle{ A = \tfrac{1}{2} bh }[/math].
- Area of a circle: [math]\displaystyle{ A = \pi r^2 }[/math]

The area of a flat object is related to the surface area and volume of a three-dimensional object.

The area under a curve can be found using integration, a concept from calculus.

## Area Media

A square metre quadrat made of PVC pipe

A circle can be divided into sectors which rearrange to form an approximate parallelogram.

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.

## Related pages

## References

- ↑ "List of Geometry and Trigonometry Symbols".
*Math Vault*. 2020-04-17. Retrieved 2020-09-24. - ↑
^{2.0}^{2.1}"Area - Math Open Reference".*www.mathopenref.com*. Retrieved 2020-09-24. - ↑ "What is Area?".
*www.mathsisfun.com*. Retrieved 2020-09-24.