1. 7.6 Apply to Sine and Cosine Ratios Hubarth Geometry

2. B CA hypotenuse leg opposite A leg adjacent to A

3. Find sin S and sin R. Write each answer as a fraction and as a decimal rounded to four places. sin S = opp. hyp = RT SR = 63 65 0.9692 sin R = opp. hyp = ST SR = 16 65 0.2462 Ex 1 Find Sine Ratios

4. Find cos U and cos W. Write each answer as a fraction and as a decimal. cos U = adj. hyp = UV UW = 18 30 = 0.60 cos W = adj. hyp = WV UW = 24 30 = 3 5 = 4 5 = 0.8000 Ex 2 Find Cosine Ratios

5. You are skiing on a mountain with an altitude of 1200 feet. The angle of depression is 21 o. About how far do you ski down the mountain? Ex 3 Find a Hypotenuse Using an Angle of Depression sin 21 o x sin 21 o = 1200 x = 1200 sin 21 o x 1200 0.3584 x 3348.2 opp. hyp. = 1200 x =

6. You want to build a skateboard ramp with a length of 14 feet and an angle of elevation of 26°. You need to find the height and length of the base of the ramp. Ex 4 Find Leg Lengths Using an Angle of Elevation sin 26 o = opp. hyp. sin 26 o x = 14 14 sin 26 o = x 6.1 x height is 6.1 ft cos 26 o = adj. hyp. cos 26 o y = 14 14 cos 26 o = y 12.6 y length is 12.6 ft

7. Find sin X and sin Y. Write each answer as a fraction and as a decimal. Practice In Exercises 3 and 4, find cos R and cos S. Write each answer as a decimal. cos R = 0.6 cos S = 0.8 cos R = 0.88 cos S = 0.47 15 34