Perimeter, Area and Volume - Area of Square and Rectangle

Understanding Area: Area is defined as the amount of flat surface or region covered by a closed two-dimensional shape. If you imagine a rectangle filled with small $1\ cm \times 1\ cm$ squares, the total count of those squares represents the area.

Standard Units: Area is always measured in square units. Common units include square centimeters ($cm^2$), square meters ($m^2$), and square millimeters ($mm^2$). Visually, $1\ cm^2$ is the space occupied by a small square with each side measuring $1\ cm$.

Properties of a Rectangle: A rectangle is a quadrilateral where opposite sides are equal and all four angles are right angles ($90^{\circ}$). In a diagram, the longer side is usually called the Length ($L$) and the shorter side is the Breadth ($B$).

Properties of a Square: A square is a special type of rectangle where all four sides are equal in length. Visually, it looks perfectly symmetrical from all sides, and its area is simply the space contained within these four equal boundaries.

The Grid Method: You can find the area of a rectangle by dividing it into a grid of unit squares. For a rectangle of $4\ cm$ by $3\ cm$, you would see $4$ columns and $3$ rows, creating a total of $12$ unit squares.

Perimeter vs. Area: It is important to distinguish between the two. Perimeter is the 'fence' or the distance around the edge, whereas Area is the 'grass' or the space inside the fence.

Consistency of Units: Before calculating area, ensure that both dimensions (length and breadth) are in the same unit. If the length is in $m$ and the breadth is in $cm$, convert one of them so they match.