1. Section 2 – Trigonometric Ratios in Right Triangles
Chapter 5
Section 2 – Trigonometric Ratios in Right Triangles

2. Basics of Right Triangles

3. Trigonometric Ratios WORDS SYMBOL DEFINITION Sine Ѳ Sin Ѳ
Sin Ѳ = opp/hyp
Cosine Ѳ
Cos Ѳ
Cos Ѳ = adj/hyp
Tangent Ѳ
Tan Ѳ
Tan Ѳ = opp/adj

4. Memorizing Trig Ratios
Just a simple little thing…
You can use SOH, CAH, TOA as the way to memorize which sides go with which trig ratios.
Sin is opp/hyp, Cos is adj/hyp, and Tan is opp/adj.

5. Finding a Few
EX 1: Find the values of the sine, cosine, and tangent for angle B.
EX 2: Find the values of the sine, cosine, and tangent for angle A.

6. The Other Three Trig Ratios
WORDS
SYMBOL
DEFINITION
Cosecant Ѳ
Csc Ѳ
Csc Ѳ = hyp/opp
Secant Ѳ
Sec Ѳ
Sec Ѳ = hyp/adj
Cotangent Ѳ
Cot Ѳ
Cot Ѳ = adj/opp
You should have noticed that each of the first three trig ratios (sin, cos, and tan) are inverses with these three.
Therefore, if sin Ѳ = 1/3, then csc Ѳ = 3.

7. Assignment
Chapter 5, Section 2
pgs #5-8,10-22E,28,30