1. Basic Trigonometry
We will be covering Trigonometry only as it pertains to the right triangle:
Basic Trig functions: 
Hypotenuse (H)
Opposite (O)
Adjacent (A)
Remember: “SOH CAH TOA”

2. Basic Trigonometry (2) Let’s Practice this:
For each triangle, find the unknown (?) side using your calculator.
57
(?)
38
30
55
45
4.50
30.0
7.60
10.0
25.0
42
9.80

3. Basic Trigonometry (3) Inverse Trig Functions
Use when you don’t know the angle, but know any two sides.

4. Basic Trigonometry (3)
Practice: Find the unknown angles (?) using inverse trig functions:
(?)
35.0
16.0
3.80
12.0
3.50
4.50
30.0
7.60
10.0
25.0
11.5
9.80

5. Basic Trigonometry (4) Pythagorean Theorem H2 = O2 + A2 or
Useful for finding the third side of a right triangle when the other two sides are known.
So now, we can find any unknown side or angle of a right triangle using either trig functions (Sin, Cos, Tan), inverse trig functions, or the Pythagorean Theorem.