1. TRIGONOMETRIC RATIOS Chapter 9.5

2. New Vocabulary  Trigonometric Ratio: The ratio of the lengths of two sides or a right triangle.  The three basic trigonometric ratios are SINE, COSINE, and TANGENT.  OPPOSITE??  ADJACENT??

3. Trigonometric Ratios Explained b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A

4. Trigonometric Ratios SINE (SOH) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Sin A = Side Opposite <A = O = a Hypotenuse H c

5. Trigonometric Ratios COSINE (CAH) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Cos A = Side Adjacent <A = A = b Hypotenuse H c

6. Trigonometric Ratios TANGENT (TOA) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Tan A = Side Opposite <A = O = a Side Adjacent <A A b

7. “ !”

8. What COLOR side is OPPOSITE <A? A

9. What COLOR side is ADJACENT TO <A? A

10. What COLOR side is the HYPOTENUSE? A

11. What is the sin of <X ? 15 8 17 Y X Z

12. What is the tan of <Y ? 12 5 13 Y X Z

13. What is the cos of <X ? 48 14 50 Y X Z

14. What are the sin, cos, and tan of <H? 3500 9100 8400 H

15. Using a Calculator to Find Trigonometric Ratios for Specific Angles  You can find the trigonometric ratios for specific angles using a calculator…  Step 1: Make sure your calculator is in DEGREES!!! Go to MODE, and select degrees if necessary.  Step 2: Select the button for the trig. function you would like to use.  Step 3: Type the angle measure into the parenthesis.  Step 4: Close parenthesis and press enter!  Step 5: Round the answer to the desired number of decimal places.

16. Using a Calculator to Find Trigonometric Ratios for Specific Angles ROUND ANSWERS to four decimal places! Example 1: What is the sine of 25 degrees? Example 2: What is the tangent of 18 degrees? Example 3: What is the cosine of 49 degrees?