There are three major types of Directions,

1. Magnetic Direction : Its a direction in which freely suspended magnet unaffected by any Magnetic field points is called Magnetic North.

Its not Geographical.

2.True Direction : Its a direction which is measured with respect to True North.

3.Compass Direction: Direction which compass Magnet points is called compass North.

Variation : Angular Difference between True North and Magenetic North is call Variation.

Note: If Magnetic North is east of True North, it is called easterly Variation. If west then Westerly Variation.

Deviation : Angular Difference Between Compass Direction and Magnetic Direction.

Isogonal Line : Line joining places of equal Variation is called Isogonal line.

Agonic/Agonal Line: Line joining places of zero Variation.

Remember these THUMB RULE for Directions:

Variation East Magnetic Least

Variation West Magnetic Best

Deviation East Compass Least

Deviation West Compass Best

C                D               M             V               T

Example:

Question: T=225*  V=6* E  D= 9* W  find M & C?

Answer:    [table]

C,D,M,V,T

228*,9*W,219*,6*E,225*

[/table]

 

Question:T=45*  V=-3*  D= +6*  find M & C?

Answer:    

 [table]

C,D,M,V,T

42* ,+6* or 6*E,48*,-3* or 3*W,45*

[/table]