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Juanita measures the angle of elevation from the ground to the top of an18-foot-tall tree as 30°. The image is of a tree whose height is 18 ft and its top is making an angle of 30 degrees with the ground. To the nearest tenth of a foot, how far is she from the tree?

2 Answers

1 vote
As shown in the picture below she and the tree are making a 30-60-90 degree triangle. In the diagram, it is shown the bottom is sqrt(3)*x the side, so she is sqrt(3)*18 or 31.1769.
Juanita measures the angle of elevation from the ground to the top of an18-foot-tall-example-1
5 votes

Answer:

Juanita is standing 31.17 ft far from the tree.

Explanation:

Angle of elevation measured by Juanita =
\theta=30^o

Height of the tree = 18 ft

Also, an image of that tree whose height is 18 ft and its top is making an angle of 30°.This means length of the image is equal to the distance at which Juanita is standing.

In fig ΔABC


(AB)/(BC)=\tan\theta


(18 ft)/(BC)=\tan 30^o=0.5773 (tan 30° = 0.5773)

BC = 31.17 ft ≈ 31.2 ft

Juanita is standing 31.2 ft far from the tree.

Juanita measures the angle of elevation from the ground to the top of an18-foot-tall-example-1
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