1. Geometry 8-2 Trigonometric Ratios

2. Vocabulary  A trigonometric ratio is a ratio of two sides of a right triangle.

3. 1 st Trigonometric Ratio  The sine (sin):

4. Examples  Write each trig ratio.  sin J  sin K

5. 2 nd Trigonometric Ratio  The cosine (cos):

6. Example  Write each trig ratio.  cos B  cos A

7. 3 rd Trigonometric Ratio  The tangent (tan):

8. Example  Write each trig ratio.  tan A  tan B

9. How to Remember  SOHCAHTOA

10. Calculator  You can use the calculator to evaluate the ratio of an angle’s measure.  Make sure the calculator is in degrees!!!  sin(22°)= cos(46°)= tan(65°)=

11. Using Trig Ratios Example  Find the measures of x and h. 24 ft

12. Another Example  Find the length of side BC.

13. Word Problem  You and your friends decide to build a bike ramp using a 4 ft piece of wood. You make a 45° angle with the ground because it will give you the most distance after takeoff. How high above the ground will the back wheel be when your bike goes off the ramp?