1. Find the missing sides. Round to the nearest tenth. 1. 2.
Two Triangles y x
25’ x
16” y

2. Lesson Objective
Students will be able to apply trigonometry functions to solve real world problems using angles of elevation and depression.

3. Angle of depression and elevation
Angle of Elevation
Angle of Depression: the angle formed by the horizontal line and the line of sight to an object below the horizontal line.
Angle of Elevation: the angle formed by the horizontal line and the line of sight to an object above the horizontal line.

4. Describe each angle as it relates to the situation.3 1 2 4

5. Find the value of x. The dotted line is parallel to the third side of the triangle. Round to the nearest tenth.
Two triangles slide 1 1.
28°
24’ x 2.
18” x
36°

6. Sample problems Sketch a picture and solve for the indicated value.
1. A surveyor stands 200 ft from a building to measure its height with a 5-ft tall theodolite. The angle of elevation to the top of the building is 35°. How tall is the building?
2. An airplane flying 3500 ft above ground begins a 2° descent to land at an airport. How many miles from the airport is the airplane when it starts its descent?

7. Clinometer
Clinometer: A tool used to measure the angles of elevation and depression.
Use the homemade clinometer to find the angle of elevation. 1.

8. Clinometer 1
Use the homemade clinometer to find the angle of elevation. 2.

9. Assignment: Angle of Elevation Worksheet