A
50x100
plot is smaller than an eighth of an acre!
The Sunday Nation
Nairobi,
13 June 2010
Julia Mothoni has a title deed for a plot of land and the size is
indicated as “0.043ha”. She is wondering: “Is this a quarter, an eight
or what measurement is it? Please give me in figures e.g. 100 x 1000, 50
x 100, 80 x 40 etc.”
Now, although we are accustomed to the imperial measurements for certain
things, this system of units is quite cumbersome and user-unfriendly.
Think about it: 12 inches make a foot, 3 feet are a yard and 1,760 yards
make a mile.
If you think those numbers are awkward, try this one: an acre of land is
the area measuring 66 feet by 660 feet. That is, 43,560 square feet.
This crazy definition has an interesting history behind it: it was
originally estimated as the size of land that one man could till using
an ox-drawn plough in one day.
These 43,560sq-feet can be obtained in many different combinations of
length and width, for example, 132ft-by-330ft or 198-by-220… and so on.
Obviously, however, some shapes are impractical: you may end up with an
acre of land which cannot fit a normal house. Imagine a plot measuring
10ft-by-4,356ft; it is one acre, but what sort of structure can you
build on it?
For this reason, surveyors try to draw plots that are “regular
rectangles”. This means that the length is approximately equal to twice
the width. This is reason you find parcels measuring 50x100, 40x80,
30x60 and so on.
The [almost] perfect regular rectangular acre would therefore measure
147.58ft-by-295.16ft. That is 147ft, 7inches by 295ft, 2inches. Urgh! I
really do hate these imperial units!
Partly because of this cumbersomeness of the imperial system,
professionals in all fields have adopted international metric units of
metres, kilograms and seconds. Consequently, surveyors do not work in
feet and acres; they use metres and hectares (symbol: ha).
One hectare is an area equivalent to a square measuring 100 metres on
all sides; that is 10,000 square metres (100m x 100m). It works out to
approximately (and I emphasize APPROXIMATELY) 2.47acres.
Now, if one hectare is roughly 2.47acres, how many acres is Muthoni’s
0.043ha? To get the answer, we simply multiply 2.47 by 0.043. The result
is 0.106 of an acre, that is, slightly more that one-tenth.
Unfortunately, however, we are used to plots of land being either
halves, quarters or eighths of an acre. Now, of these three, the eighth
is closest fraction to a tenth. This raises a popular primary school
question: which is bigger – an eighth or a tenth?
If you don’t know an eighth is one divided by eight; and that equals
0.125. Thus, clearly, Muthoni’s 0.106acre (0.043ha) is SMALLER than an
eighth. To get the dimensions of this plot, we need to first evaluate
its area in square feet. This is 0.106 x 43,560 = 4,617sf. Therefore, if
the plot is a regular rectangle, it will measure approximately
48ft-by-96ft; and the seller probably advertised it as 50x100.
Muthoni shouldn’t feel cheated: she must have seen the title deed before
buying and it clearly said that the size is “0.043ha or thereabouts”.
This is what she bought, not “50x100”. In any case, even the common
50x100 plots are smaller than an eighth of an acre! Do the math and you
will see.
Finally, I cannot understand why the plot was surveyed as 0.043ha:
0.045ha would have been a more convenient size. The dimensions then come
to 15m-by-30m. This is how the popular 50x100s are surveyed. The exact
measurements are 49.21x98.42.
 |
 |