1. Warm-Up Make all units the same then solve for the missing side 32 in.B C x
32 in.
2 ft. 4 in.

2. Primary Trigonometric Ratios
LG: I can use the primary trig ratios to solve for missing sides or angles in a right triangle

3. Right Triangle Terminology IIƟ
“theta”
Opposite
Adjacent
Opposite and adjacent sides switch depending on which acute angle the triangle is being considered
The hypotenuse is always opposite the right angle
Theta represents an unknown angle

4. Primary Trig Ratios To remember use: SOH CAH TOA
Primary trig ratios (sine, cosine, and tangent) and be used to solve for:
a missing angle if you know 2 sides, or
a missing side if you know an angle and 1 side
𝑠𝑖𝑛𝜃= 𝑜𝑝𝑝𝑜𝑠𝑖𝑡𝑒 ℎ𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠𝑒 𝑐𝑜𝑠𝜃= 𝑎𝑑𝑗𝑎𝑐𝑒𝑛𝑡 ℎ𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠𝑒 𝑡𝑎𝑛𝜃= 𝑜𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑎𝑑𝑗𝑎𝑐𝑒𝑛𝑡
To remember use: SOH CAH TOA

5. Example 1 Solve for the missing side Label the sides of the triangle
Determine which trig ratio to use Q P R x
18.4 cm

6. Example 2 Find the measure of angle A Label the sides of the triangle
Determine which trig ratio to use
17 cm A B C
11 cm

7. Example 3 Solve the following triangle (find all unknown values)
Hint: May use trig ratios and/or Pythagorean theorem L M N
51° x
33 m y z

8. Homework
Pg # 3 – 10