Marta is standing 4 ft behind a fence 6 ft 6 in. tall. When she looks over the fence, she can just see the top edge of a buildin
g. She knows that the building is 32 ft 6 in. behind the fence. Her eyes are 5 ft from the ground. How tall is the building? Give your answer to the nearest half foot.
1 answer:
Answer: 93ft
Explanation: Martha's eyesight make an angle with the fence, this is solved as a triangle problem.
We first convert all the dimensions to inches using the fact that 12 inches make 1 ft.
To solve for the angle
Tan § = 18/48 = 0.375
§ = tan^-1 of 0.375 = 20.55°
This same angle elevates to the edge of the building
Tan 20.55 = 399/x
x = 399/tan 20.55
x = 1040 inches
Height of building = x + height of fence
Height of building = 1040 + 78 = 1118 inches
Converting back to ft it becomes
1118/12 = 93 ft 2 inches
Approximately 93ft
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