HELP!! Geometry?
2017-06-08 10:37 pm
Dr. Black is standing 13 feet from a streetlamp. The lamp is making his shadow 9 feet long. He estimate hat the angle of elevation from the tip of his shadow to the top of the streetlamp is 50 degrees. To the nearest foot, the streetlamp is about ____.
回答 (4)
2017-06-08 10:48 pm
✔ 最佳答案
So the distance from the tip of the shadow to the lamppost is 13ft+9ft=22ft.Height of lamppost (lets call that h) is the opposite side from the angle, and the 22ft (lets call that d) is the adjacent side of the triangle.
Tan(50)= (h/d) [opposite over adjacent right?]
tan(50) = h/22
1.19175 =h/22
multiply both sides by 22,
26.21 ft
2017-06-08 10:56 pm
Refer to the diagram as shown.
AB : the streetlamp
CD : Dr. Black
DE : The shadow of Dr. Black
In ΔABE :
tan50° = AB / BE
tan50° = AB / [(13 + 9) ft]
AB = 22 tan50° ft
AB = 26 ft (to the nearest ft)
The streetlamp is about 26 ft.
AB : the streetlamp
CD : Dr. Black
DE : The shadow of Dr. Black
In ΔABE :
tan50° = AB / BE
tan50° = AB / [(13 + 9) ft]
AB = 22 tan50° ft
AB = 26 ft (to the nearest ft)
The streetlamp is about 26 ft.
2017-06-08 10:40 pm
to get hit by a car, LOOK OUT DR BLACK!!!
2017-06-08 10:44 pm
h is the height of the lamp
tan(50°) = h/22
h = 22tan(50°)
tan(50°) = h/22
h = 22tan(50°)
收錄日期: 2021-04-24 00:28:50
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