1. Warm Up 18° 10 cm x 55 x 9cm Find the length of sides x and y y

2. Homework Answers p. 308 2. 23.64. 1.4 6.3.314. w= 286, z=571 16.w= 82, z=15418. w=520, z =480 p. 314 2.x=102, y=644. x=54, y=64 6.x=28, y=2612. x=20, y =10

4. Right Triangles Trigonometry Wednesday 4/30/08 Chapter 8 Sections 5 and 6 Finding Angle Measures

5. Parts of a Right Triangle Review Hypotenuse is always the side opposite 90° Angle A is the reference angle B A C Side AC is adjacent to the reference Angle A Side BC is opposite the reference Angle A

6. Trigonometry is also used to find the measures of the acute angles of a right triangle Sine, Cosine and Tangent ratios are still used. You are starting with the side ratios and essentially working backward to get the angle measure.

7. C B A Leg opposite  A cos  A = leg adjacent  A hypotenuse Example : Find BC and  A and  B 15 9 AC = 12 BC² +9² = 15² Leg adjacent  A

8. C B A Abbreviated form cos  A = adj hyp Leg adjacent  A Cos  A = leg adjacent  A hypotenuse Example : Find cos  A and  B 6 10

9. C B A Leg opposite  A Tan  A = leg opposite  A Leg adjacent  A hypotenuse Example : Find AB and  A and  B 5 12 AB = 13 5² +12² = AB²

10. C B A Abbreviated form tan  A = opp adj Leg adjacent  A Tan  A = leg opposite  A leg adjacent  A hypotenuse Example : Find tan  A and  B 3 5 Leg opposite  A

11. A tipping platform is a ramp used to unload trucks. How high is the end of an 80ft ramp when it is tipped by 42°? h 80 ft ramp 42° 42° is the reference angle. Which side is 80 ft? Which side is represented by h?

12. Examples 38° 24cm x 50° x 9 Find the lengths of sides x and y y y

13. Homework p. 302 2-18 even And p. 314 2-12 even No quiz tomorrow!