Question

The fore bearing of line AB is 15°30'. What will be the back bearing of the line AB?

• A. 196°30'
• B. 197°30'
• C. 165°30'
• D. 195°30'

Hint:

To calculate the back bearing, add 180° to the fore bearing. If the result exceeds 360°, subtract 360°.

Answer 1

The Correct Option is A

Step 1: Understanding Back Bearing.
The back bearing is the opposite direction of the fore bearing. To calculate the back bearing, we add 180° to the fore bearing. If the result is greater than 360°, subtract 360°.
Step 2: Calculating the Back Bearing.
The fore bearing of line AB is 15°30'. The back bearing will be: \[ \text{Back bearing} = 15°30' + 180° = 195°30'. \] Since the result is less than 360°, there is no need to subtract 360°.
Step 3: Conclusion.
Therefore, the back bearing of line AB is 195°30', making option (4) the correct answer.

Final Answer: \[ \boxed{195°30'} \]