1. Angles of Elevation & Depression
I. Right Triangles.
A) The 3 angles in any triangle add up to 180°.
B) If you know the measure of 2 angles in a triangle, you can find the value of the 3rd angle using... 1)
C) If you know the measure of 2 sides in a right triangle, you can use the Pythagorean Theorem to find the 3rd side.
1) a2 + b2 = c2 (where c = the hypotenuse)

2. Angles of Elevation & Depression
II. Using Trig to find missing sides/angles of a right Δ.
A) If you know 2 sides, you can find the measure of the angles using inverse trig (sin-1, cos-1, or tan-1). 1)
2) Set your calculator to degree mode.
B) If you know 1 side and 1 angle, you can find the other sides using trig. (use degree mode)
2) Solve by cross multiplying. Then solve for the variable.

3. 4.8 Trig Applications and Models
III. Angles of Elevation / Angles of Depression.
A) The angle an object makes from the horizon (straight out) to another object above or below it creates an angle of elevation or depression.
1) Elevation: Looking up from the horizon.
2) Depression: Looking down from the horizon.
elevation
Horizon depression
CW: Applications # 1 (work in teams of 2)