Asked by Anonymous

When the angle of elevation of the sun is 30° the shadow of a vertical tower is 20m longer than when the elevation of the sun is 60°.find the height of the tower

Answers

Answered by Reiny
After making your sketch, .....
Let the shadow's length at 60° be x m, let the tower height be h
Given: the length of the shadow at 30° = x+20 m
so ... tan60 = h/x
h = xtan60
and tan 30 = h/(x+20)
h = tan30(x+20)

then xtan60 = tan30(x+20)
xtan60 = xtan30 + 20tan30
x(tan60 - tan30) = 20tan30
x = 20tan30/((tan60 - tan30) = ....

then you find h in h = xtan60

OR

Nice to have those 30° and 60° angles, since you have the 30-60-90 triangle
with corresponding sides in the ratio of 1:√3:2

By the 30-60-90 ratios:
√3 x / x = (x+2)/(√3x)
√3 = (x+20)/(√3x)
3x = x+20
x = 10
then h = √3x = √3(10) = appr 17.321.... m

You will get the same answer from my first solution.
Answered by oobleck
Reiny's first solution can be made at least to look less complicated if you are comfortable using the cotangent function.
h cot30° - h cot60° = 20
h = 20/(cot30° - cot60°) = 20/(√3 - 1/√3)
Answered by Ayoola joy
I need the real solution to the question
Answered by Esther
i need the real solution t
o this answer pls
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