If FB of line PQ is N 35' W and FB of line QR is S 40° W, find angle PQR.
A)80
B)75
C)95
D)85

Question

Quizplus · Accepted Answer

The angle PQR can be found by adding the internal angles of the triangle formed by lines PQ and QR. The FB (forward bearing) of line PQ is N 35° W, which means it makes a 35° angle with the north direction towards the west. The FB of line QR is S 40° W, which also makes a 40° angle with the south direction towards the west. To find the internal angle PQR, we subtract the smaller angle from the larger one, which gives us 40° - 35° = 5°. However, since these are external angles to the direction of the turn, the actual internal angle is 180° - 5° = 175°. This calculation is incorrect based on the misunderstanding of how bearings work in the context of calculating the angle between two lines. The correct approach is to understand that the bearing of PQ (N 35° W) and QR (S 40° W) implies a change in direction that can be directly calculated by considering the north as a reference point and the direction of the turn. The correct calculation involves understanding that the angle between the two bearings is the sum of their deviations from North, which is 35° + 40° = 75°.

If FB of Line PQ Is N 35' W and FB