1. Section 9 – 3 Section 9 – 3 Angles of Elevation & Depression Objectives: To use angles of elevation and depression to solve problems

2. Angle of Elevation The angle ABOVE a horizontal line

3. Angle of Depression The angle BELOW a horizontal line

4. Angles of Elevation & Depression

5. Example 1 Identifying Angles of Elevation & Depression Describe each angle as it relates to the situation shown. A)∠1 B)∠4 C)∠2 D)∠3

6. Example 2 Trig Word Problems Write a situation for each diagram. Then solve for the missing length or angle measure. A)

7. B) C)

8. D) E)

9. HOMEWORK Find missing angles & lengths for each word problem. Recognize how diagrams are drawn (tomorrow you will have to draw your own!)

10. Section 9 – 3 Section 9 – 3 Continued… Objectives: To use angles of elevation and depression to solve problems

11. Example 3 More Trig Word Problems A)You sight a rock climber on a cliff at a 32°angle of elevation. The horizontal ground distance to the cliff is 1000 ft. Find the line-of- sight distance to the rock climber.

12. B)A surveyor stands 200 ft from a building to measure its height with a 5 ft high theodolite. The angle of elevation to the top of the building is 35°. How tall is the building?

13. C)A tree 30 feet high casts a shadow 45 feet long. Find the measure of the angle of elevation of the sun.

14. D)A flagpole is 26 feet high and the distance from the line of sight at the top of the flagpole to a person on the ground is 35 feet. What is the angle of depression?

15. E)An airplane flying 3500 feet about ground begins a 2° descent to land at an airport. How many miles from the airport is a point directly underneath the airplane when it starts its descent?

16. F)To approach runway 17 at the Ponca City Municipal Airport in Oklahoma, the pilot must begin a 3° descent starting from an altitude of 2714 feet. The airport altitude is 1007 feet. How many miles from the runway is the airplane at the start of this approach?

17. HOMEWORK Complete Trigonometry Word Problems Worksheet