Theory of Area Calculations [0:13]

Many people learn the method of coordinates to calculate the area of geometric figures. The known information required to do this are the coordinates of the figure’s vertices. But these can be derived, using anything for the origin of the coordinate system if latitudes (∆ northings) and departures (∆ eastings) for each of the figure’s lines are known. The method of calculating area by coordinates leads to memorization of a rote process. But why does this work? Understanding the inner workings of the process also allows the learner to understand the double meridian distance method (DMD). The additional knowledge can be useful when calculating the area of figures as any of these methods is quite prone to user error (mistakes). By using a completely different set of values, the results of the coordinate and DMD methods can be compared to verify the result. The theory of area calculation is thus helpful in ensuring the correct result is achieved. Running time 13 minutes.

You will learn…

• How area by coordinates is carried out (again)
• The basic DMD method process
• The graphic illustration of the DMD method which can be seen to be intuitively be the same approach as the coordinate method
• An easy approach when using the coordinate method to systematically alter the known coordinates so that different values are used to determine if the area obtained matches.