1. Lets look at an application problems: The highest bridge in the world is the bridge over the Royal Gorge of the Arkansas River in Colorado. Sightings to the same point at water directly under the bridge are taken from each side of the 880-foot long bridge, as indicated in the figure how high is the bridge?
880 ft
69.20
65.50
Step 1 find the third angle using the sum of the angles of a triangle.
C = 180 – 69.2 – 65.5 = 45.30 b
Step 2 Since we know C and c and all the angles we will use c/Sin C = (pick which one you want to find first) C

2. You Try
#41) An aircraft is spotted by 2 observers who are 1000 feet apart. As the airplane passes over the line joining them, each observer takes a sighting of the angle of elevation to the plane observer 1 is 400 observer 2 is 350. How high is the airplane?
35º
40º
1000 ft