If you have a scaled card with the indication of parallels and meridians, you will be able easily to learn any distances between points, including to calculate continent extent.
It is required to you
- - card with the indication of meridians and parallels;
- - calculator;
- - ruler.
Instruction
1. First of all, for calculation of extent of the continent from the North on the South, find extreme northern and southern points, then determine their width. Look, on the card there are horizontal lines – parallels. Find the parallels, next to required points, and determine their width (it is specified cards on the right and at the left). If the point is located between them, try to learn width approximately, add to the found width arch length from a parallel to a point in degrees.
2. Having received the width of both points, find distance between them in degrees. If points are located in one hemisphere (for example, North America or Australia), just subtract smaller from bigger value. If they are in different hemispheres (for example, Africa or South America), then, on the contrary, add modules of values (as width – distance from a point to the equator).
3. Knowing continent length in degrees, receive its extent in kilometers. For this purpose increase the number of degrees by length of each degree. Consider that length of one degree on a meridian of 111.12 km.
4. To find continent length from the East on the West, find the longitude of extreme east and extreme western point. Then count by means of meridians (vertical lines) longitude in the same way, as well as width. If both points are located in east or western hemisphere, just subtract from bigger value smaller to receive continent length in degrees if in different – add modules of values (for Africa, Eurasia), or subtract them from 180º and add the received differences (for example, for America). Having increased the number of degrees by 111.3 km (length of one degree on a parallel), you receive continent length in kilometers.
5. It is possible to arrive easier way, for this purpose arm with a good exact ruler. Measure continent extent in the chosen direction by means of a ruler, and then transfer the received number of centimeters to kilometers according to the specified scale.