# Measuring Area in Square Units

We will discuss here about measuring area in square units.

We know, looking at a glance it is not easy to tell which figure is having the greater area. We need to measure the area of the figure. Now we will learn how area is measured in square meter, square centimeter and square kilometer.

Square unit is a square whose each square is 1 unit (1 m, 1 cm, 1 mm). A square of side 1 mm, 1 cm, 1 m is usually taken as a unit of area.

Consider some of the following examples for measuring area:

 (i) Suppose, take a cardboard and then place circles of equal radii to cover the entire surface. After placing the circles we see that some space is left between the circles. So, we cannot get the correct area of the figure. (ii) Let us take a cardboard and then place square tile to cover the entire surface. We see no space is left in between and then we count the number of squares. We find in this figure, the number of squares is 24. So, the area of the figure is 24 square units. (iii) Let us take a cardboard and make triangles to cover the entire surface such that two triangles make a square. The total number of triangles is 32. So, the total number of squares is 16. From the above example (ii) and (iii), we observe that the shape is covered and the outlines are repeated in such a way that there are no gaps and no overlaps in between the outlines, a continuous pattern is created. Such a created pattern with no gaps and overlaps is called tessellation.

Thus, we observe that a triangle and a square can tessellate but circles cannot tessellate as some gap is left between two or more circles.