Area is the amount of space taken up by a surface. The areas and perimeters of simple figures such as squares and rectangles can be calculated using formulae. The perimeter of a shape is the total length of all of its sides.
Perimeters are measured using the units of length, i.e. metres.
There are two basic units for measuring area:
 A square metre is the area occupied by a square with each side 1 metre long. It is written as 1 m^{2}.
 An are is the area occupied by a square of length 10 m.
Other common units for area are:
10 000 cm^{2} = 1 m^{2} 

1 km^{2}= 10^{6 }m^{2} 

1 ha= 10 000 m^{2} 
Area and Perimeter Formulae
Shape

Perimeter


P= 4 × l = 4l 
A = length × width = l^{2} 

P = 2b + 2h 
A = base x height = b × h = bh 

P = a + b + c 
A= half × base × height 

P = 2b + 2a 
A = base × height = bh 

P = Sum of all sides = 4b 



Perimeter is called thecircumference C = 2r = d 
A = r^{2} is a special number approx. 3.1416 (to 4 d.p.) or or 