Since the length of a single grid square is 1m, then its area is:

Now, to compute the area of the given section we will use the following diagram.
To compute the area of each triangle we will use the following formula for the area of a triangle:

And to compute the area of the rectangle we will use the following formula:

Therefore the area of triangle A is:

The area of triangle B is:

The area of triangle C is:

The area of triangle D is:

The area of rectangle E is:

Finally, the area of the given section is:

Answer:
The area of a single grid square is:

The approximate area of the section that will be paved is:
