1. Review for Test Get out important paper # 5 and a calculator

2. 5. A wireless company erects an 85-foot vertical cellular phone tower. Find the angle of elevation to the top of the tower from a point on the ground 110 feet from its base. A. 63.2° B. 45.2° C. 37.7° D. 52.3°

3. A wall is leaning 6° from the vertical toward you. You are standing 40’ from the base of the wall, and the angle of elevation from your feet to the top of the wall is 22°. Find the height of the wall to the nearest tenth of a foot.

4. Methods we currently have to solve triangles… Triangle Sum Theorem (angles add up to 180) Pythagorean Theorem SOHCAHTOA Law of Sines But will they always work??????

5. Solve a triangle: a = 9, b = 3 and c = 11

6. We are going to have to have another method!!!! Law of Cosines: If you are looking for a side use these: a 2 = b 2 + c 2 – 2bc cos A b 2 = a 2 + c 2 – 2ac cos B c 2 = a 2 + b 2 – 2ab cos C

7. –Law of Cosines: If you are looking for an angle, use these:

8. Solve a triangle: a = 9, b = 3 and c = 11

9. Solve this triangle: A = 108 , b = 10 and c = 6.5

12. Mount St. Helens' lava dome in August 1981, as viewed from a photo station, 1/2 mile away. In this view the dome is 535 feet high and nearly 1/4 mile wide.

13. Mount St. Helens' lava dome in August 1981, as viewed from a photo station, 1/2 mile away. In this view the dome is 535 feet high and nearly 1/4 mile wide, making it taller than a 44-story building (or, nearly the height of the Washington Monument) and wider than the length of four football fields. Compare with image taken August 12, 1985 from the same location with the same camera. AC= BC= Use SOHCAHTOA to find the the measure of Angle A.

14. A volcanologist at A made EDM measurements of a lava dome as shown. Use the Law of Cosines to find BD. Then find the height of the dome. BD = _______________ Height of dome = _______________