Area measures the space inside a two-dimensional figure. The areas of the following figures can be shown as a green region by pressing the button below the figure. Different shapes may have different formulas to calculate their areas.

Figure	Formula
Square	$A=s^2$
Rectangle	$A=\ell w$
Triangle	$A=\frac{1}{2}bh$
Circle	$A=\pi r^2$

Three-dimensional shapes can also have their area measured. In this case it is referred to the surface area of the shape, which can be visualized with the help of a net of the solid.

Area is measured in square units. A square unit is defined as the area of a square with side length of $1$ unit. For example, a square inch is the area of a square with side length of $1$ inch.