Benhur is standing #200# feet from the base of a tall building. If he determines that the angle of elevation from the ground to the top of the building is #50# degrees, how tall is the building?

2 Answers
Feb 22, 2018

#238.4# feet high

Explanation:

The question describes a right-angled triangle (We assume the building is vertical and the ground is horizontal giving an angle of #90°#

The angle of #50°# where Benhur is standing is the angle between the ground and the line to the top of the building.

The distance of #200# feet is the adjacent side and the height of the building is the opposite side, #x,# which we need to find.

Therefore we can use the Tan ratio.

#x/200 =tan50#

#x = 200 xx tan 50#

#x = 238.4# feet

Feb 22, 2018

The building is #238.4\ ft# tall.

Explanation:

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# #
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In a right triangle, the hypotenuse is the longest side, an "opposite" side is the one across from a given angle, and an "adjacent" side is next to a given angle.
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For acute angle #\theta# in a right triangle, the trigonometric ratio's are:

#sin(\theta )=\frac{\text{Opposite}}{\text{Hypotenuse}}#
#cos(\theta )=\frac{\text{Adjacent}}{\text{Hypotenuse}}#
#tan(\theta )=\frac{\text{Opposite}}{\text{Adjacent}}#

# #
# #
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We are given with:

#\text{Adjacent}=200\ ft# #\ \ \ \ #and#\ \ \ \ # #\theta = 50^{\circ}#
Let's say the required height of the building is #x# feets, which represents the #Opposite#.

By applying the trigonometric ratio of #tan#, we can find the value of #x#.

#tan(50^{\circ })=\frac{x}{200}#

Multiply both sides by 200, switch sides and then simplify to get:

#x=238.4\ ft#