1. Trigonometric Ratios in Right Triangles

2. Trigonometric Ratios are based on the Concept of Similar Triangles!

3. All 45º- 45º- 90º Triangles are Similar! 45 º 2 2 1 1 1

4. All 30º- 60º- 90º Triangles are Similar! 1 60º 30º ½ 60º 30º 2 4 2 60º 30º 1

5. All 30º- 60º- 90º Triangles are Similar! 10 60º 30º 5 2 60º 30º 1 1 60º 30º

6. Naming Sides of Right Triangles   

7. We will be learning 3 trig ratios Sine- Abbreviation is Sin (but you pronounce it Sign, not Sin!!!) Cosine- Abbreviation is Cos Tangent- Abbreviation is Tan

8.  The Trigonometric Ratios (The SOHCAHTOA model)

9. A little trick to help you remember… Some Old Horse, Caught Another Horse, Taking Oats Away

10. Find the value of each of the trigonometric functions of the angle Adjacent 12 13 c = Hypotenuse = 13 b = Opposite = 12

13. In order to use your calculator to find trigonometric ratios, it MUST be in degree mode!!!! Hint: Before taking ANY test that might have trig on it, change the mode to Degree to be safe (EOC, ACT, Semester Exam…)

14. Use a calculator to find each value. Round to the nearest ten thousandth.

17. Solving a Problem with the Tangent Ratio 60º 53 ft h = ? We know the angle and the side adjacent to 60º. We want to know the opposite side. Use the tangent ratio: 1 2 Why?