# Difference between Fore bearing and Back bearing

**Fore Bearing (F.B****)**

**i)** Fore bearing is the bearing of the line in the forward direction of surveying.

**ii)** The formula used to calculate the fore bearing of the progressive line F.B = B.B ± 180° { + sign when B.B less than 180° and – sign when B.B more than 180°}.

**Back Bearing (B.B)**

**i)** Back bearing is the bearing of the line in the opposite direction of surveying.

**ii)** The formula used to calculate the back bearing of line B.B = F.B ± 180° { + sign when F.B less than 180° and – sign when F.B more than 180° }.

*Read Carefully: *

*Bearing** represents a measurement of angles w.r.t clockwise (examples: S 77° W or N 89°45́ E) or anticlockwise ( S 69° E and N 55° W) direction or angles w.r.t clockwise direction in surveying, where angle simply represent a degree in geometry.*

**Example:-**

**322**°

**202**°

**300**°

**120**°

** Question asked in comments:**

if B.B or F.B is 180° then how we calculate:

Well friends, as we sight through compass from A to B point, we already came to know what is fore bearing.

**Here we got a new question: Please comment for any query.**

**Question:**The bearing of AB = N40W, bearing of BC = S70°E, then the value of ∠ABC is 3

**0° (anticlockwise)(-ve).**

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Very helpful for graduation in geography

Thank You Very Much 🙂

How do you get the fore bearing when the line AB bearing is N29°16’E

Fore Bearing of AB is 29°16′ and

Back bearing of AB is 29°16′ + 180° = 209°16′

How do you get the distance when the line AB bearing is N29°16’E

As we have founded the fore bearing and back bearing, now just measure the distance i.e. AB between them with the help of chain or tape. But the traverse should be completed.

How to calculate if total included angle is Greater that 360 and deferent between the bearing is already 180

How do I calculate reverse bearing given total bearing is greater than 360° ?