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
Question: T=225* V=6* E D= 9* W find M & C?
Question:T=45* V=-3* D= +6* find M & C?
42* ,+6* or 6*E,48*,-3* or 3*W,45*