1. Precalculus PreAP/Dual, Revised ©2017 §6.1B: Directional Bearing
Section 6.1B
Precalculus PreAP/Dual, Revised ©2017
2/24/2019 3:05 AM
§6.1B: Directional Bearing

2. §6.1B: Directional Bearing
Bearing and Course
When ships or planes navigate, they need to have a simple way of explain what direction they are traveling or called a bearing.
It is established as 𝑵 or 𝑺
It is an acute angle that is ALWAYS measured from the vertical (𝒚-) axis
The last part is establishing an 𝑬 or 𝑾 direction
The course of this measurement starts at the north pole
2/24/2019 3:05 AM
§6.1B: Directional Bearing

3. §6.1B: Directional Bearing
Example 1
Draw the bearing and identify the course degree of the direction, 𝑵𝟔𝟎°𝑬.
2/24/2019 3:05 AM
§6.1B: Directional Bearing

4. §6.1B: Directional Bearing
Example 2
Draw the bearing and identify the course degree of the direction, 𝑺𝟕𝟎°𝑬.
2/24/2019 3:05 AM
§6.1B: Directional Bearing

5. §6.1B: Directional Bearing
Example 3
Draw the bearing and identify the course degree of the direction, 𝑵𝟕𝟐°𝟏 𝟖 ′ 𝑾.
2/24/2019 3:05 AM
§6.1B: Directional Bearing

6. §6.1B: Directional Bearing
Your Turn
Draw the bearing and identify the course degree of the direction, 𝑺𝟑𝟓°𝑾.
2/24/2019 3:05 AM
§6.1B: Directional Bearing

7. §6.1B: Directional Bearing
Example 4
A jeep leaves its present location and travels along bearing 𝑵𝟔𝟐°𝑾 for 29 miles. How far north and west of its original position is it?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

8. §6.1B: Directional Bearing
Example 5
A private yacht travels from Myrtle Beach, SC to Freeport, Bahamas at a bearing of 𝑺 𝟏.𝟒° 𝑬 for 428 nautical miles (irrelevant). The yacht averages a speed of 20 knots per hour. (a) How long will it take the yacht to make the trip? (b) How far east and south is the yacht after 12 hours? (c) A plane leaves Myrtle Beach to Freeport. What course should it take?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

9. §6.1B: Directional Bearing
Example 5a
A private yacht travels from Myrtle Beach, SC to Freeport, Bahamas at a bearing of 𝑺𝟏.𝟒°𝑬 for 428 nautical miles. The yacht averages a speed of 20 knots per hour. (a) How long will it take the yacht to make the trip?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

10. §6.1B: Directional Bearing
Example 5b
A private yacht travels from Myrtle Beach, SC to Freeport, Bahamas at a bearing of 𝑺𝟏.𝟒°𝑬 for 428 nautical miles. The yacht averages a speed of 20 knots per hour. (b) How far east and south is the yacht after 12 hours?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

11. §6.1B: Directional Bearing
Example 5b
A private yacht travels from Myrtle Beach, SC to Freeport, Bahamas at a bearing of 𝑺𝟏.𝟒°𝑬 for 428 nautical miles. The yacht averages a speed of 20 knots per hour. (c) A plane leaves Myrtle Beach to Freeport. What course should it take? (drawing not to scale)
2/24/2019 3:05 AM
§6.1B: Directional Bearing

12. §6.1B: Directional Bearing
Example 6
The course for a boat race starts at Point A and proceeds in the direction of 𝑺 𝟓𝟐° 𝑾 to Point B, then in the direction of 𝑺 𝟒𝟎° 𝑬 to point C, and finally back to Point A. Point C lies 8 km directly south of Point A. What is the total distance of this race?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

13. §6.1B: Directional Bearing
Example 6
The course for a boat race starts at Point A and proceeds in the direction of 𝑺 𝟓𝟐° 𝑾 to Point B, then in the direction of 𝑺 𝟒𝟎° 𝑬 to point C, and finally back to Point A. Point C lies 8 km directly south of Point A. What is the total distance of this race?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

14. §6.1B: Directional Bearing
Example 6
The course for a boat race starts at Point A and proceeds in the direction of 𝑺 𝟓𝟐° 𝑾 to Point B, then in the direction of 𝑺 𝟒𝟎° 𝑬 to point C, and finally back to Point A. Point C lies 8 km directly south of Point A. What is the total distance of this race?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

15. §6.1B: Directional Bearing
Example 6
The course for a boat race starts at Point A and proceeds in the direction of 𝑺 𝟓𝟐° 𝑾 to Point B, then in the direction of 𝑺 𝟒𝟎° 𝑬 to point C, and finally back to Point A. Point C lies 8 km directly south of Point A. What is the total distance of this race?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

16. §6.1B: Directional Bearing
Your Turn
An airplane travels at 165 mph for 2 hours in a direction of 𝑺𝟔𝟐°𝑾 from Chicago. How far south and west is the plane from Chicago?
2/24/2019 3:05 AM
§6.1B: Directional Bearing

17. §6.1B: Directional Bearing
Assignment
Worksheet
2/24/2019 3:05 AM
§6.1B: Directional Bearing