areas

1. Computation of areas in surveying is the process of determining the area of a
given plot of land or a structure by using various methods and rules. Some of
the common methods are:
Mid-ordinate method: This method divides the plot into strips of equal width
and calculates the area by multiplying the common distance by the sum of
mid-ordinates.
Average ordinate method: This method calculates the area by multiplying the
length of the base line by the average of all the ordinates.
Trapezoidal rule: This method assumes that the boundaries between the ends
of ordinates are straight and calculates the area by multiplying the common
distance by half of the sum of the first and last ordinate and twice the sum of
the intermediate ordinates.
Simpson’s rule: This method assumes that the boundaries between the ends
of ordinates form an arc of a parabola and calculates the area by multiplying
the common distance by one-third of the sum of the first and last ordinate,
four times the sum of the even ordinates and twice the sum of the odd
ordinates.
Graphical method: This method uses a tracing paper with a grid of squares to
count the number of squares enclosed by the plot and multiply it by the area
of one square.