Area
area explained  surface area of humans
Area explained
Area is measured in square metres (m^{2}).
It is important to realise that m are not the same as m^{2}.
The area of a triangle is half the area of the smallest rectangle
that will enclose it, and so the area of the triangle is half
the area of that rectangle.
To find the area of a circle we need to use pi. The area of a
square with each side of length r will have area r^{2}.
The proportion of that square covered by a quarter of a circle
happens to work out to ^{π}/_{4}, so the
area of the quarter circle is ^{π}/_{4} times
r^{2}. This means a whole circle's area is πr^{2}.


Calculating Area
Area of a rectangle:
base x height
[or] length x width
Area of a triangle:
^{1}/_{2} base x height
Area of a circle:
pi x radius^{2}
π·r^{2}
Surface area of a sphere:
4·π·r^{2} 
Random facts – surface area of humans
An average adult woman has a surface area of about 1.6 m^{2},
while an average adult man has a surface area about 1.8 m^{2}.
The lungs have a greater surface area – about 75 m^{2}.
The intestines have even more – their total length is only about 7.58.5
m but inside them they have an enormous number of tiny projections
called villi (which are in turn covered in microvilli), giving them
a total surface area of as much as 200 m^{2}.
