The area of a figure indicates the number of unit square boxes it can hold. The square
box could be a square inch, a square ft, a square meter etc. and this would
determine the unit of area measured. It is easier to count boxes in a square or
in a rectangle figure (which is same as multiplying the length and the width)
but it would be difficult if the figure is enclosed by slanted or curved lines;
in which case a formula may be derived by using some other properties; as we
will see later in case of triangles and circular figures.