I need help with my test review questions.

Question

13. A safety regulation states that the maximum angle of elevation for a rescue ladder is 72°. A fire

department’s longest ladder is 110 feet. What is the maximum safe rescue height?

14. From the time a small airplane is 100 feet high and 1600 ground feet from its landing runway, the plane

descends in a straight line to the runway (creating a hypotenuse). Determine the plane’s angle of

descent.

15. An electrician is running wire from the electric box on a house to a utility pole 75 feet away. The angle

of elevation to the connection on the pole is 16°. How much wire does the electrician need?

Answer 1

13. A safety regulation states that the maximum angle of elevation for a rescue ladder is 72°. A fire

department’s longest ladder is 110 feet. What is the maximum safe rescue height?

 

DRAW THE RIGHT TRIANGLE with base angle measuring 72^o and label the vertical height h (opposite the base angle).

h = 110 sin 72 = 104.6 ft.

 

For these other two problems, make a drawing (triangles) and use basic Triangle Trigonometry.

Answer 2

Yeny, I'll do the first and I bet you can do the rest. First, draw a picture so you can see what you are dealing with.

 

110/sin90 = b/sin72

110sin72 = bsin90

b = 110sin72/sin90

 

Since sin90 = 1, b = 110sin72 = 104.62 ft