
An observer 1.5 m tall is 28.5 m away from a tower. The angle of elevation of the top of the tower from his/her eyes has measure 45 degrees. What is the height of the tower?
A. 28.5 m
B. 30 m
C. 27 m
D. 1.5 m
Answer
556.2k+ views
Hint: In order to solve this problem firstly draw the diagram then apply the concept of trigonometric angles in the triangles with the help of given data. Doing this will take you to the actual height of the tower.
Complete step-by-step answer:
The diagram for solving this problem has been drawn above. Lengths are in meters and angles are in degrees.
CE is the height of man = 1.5 m
AD is the height of the tower = BD + AB = 1.5 + AB (As BD and CE are opposite sides of rectangle BDEC therefore BD = CE)
So, we have to find AD which is equals to 1.5 + AB ……(1)
So, if we find AB we can find AD from (1).
On considering triangle ABC from the figure we can say that,
tan 45 = 1 = $\dfrac{{{\text{AB}}}}{{{\text{BC}}}}$ ……(2)
We know that BC = DE =28.5 ($\because $ they are the opposite sides of the rectangle)
On putting the value of BC in (2) we get the equation as:
AB=(1)(28.5)=28.5
So, AB = 28.5
Height of the tower AD = 28.5 + 1.5 = 30 (From (1))
Hence, the height of the tower is 30 meters.
So, the correct option is B.
Note: In this type of problem students often make the mistake of excluding the height of the man in height of the tower.
Complete step-by-step answer:

The diagram for solving this problem has been drawn above. Lengths are in meters and angles are in degrees.
CE is the height of man = 1.5 m
AD is the height of the tower = BD + AB = 1.5 + AB (As BD and CE are opposite sides of rectangle BDEC therefore BD = CE)
So, we have to find AD which is equals to 1.5 + AB ……(1)
So, if we find AB we can find AD from (1).
On considering triangle ABC from the figure we can say that,
tan 45 = 1 = $\dfrac{{{\text{AB}}}}{{{\text{BC}}}}$ ……(2)
We know that BC = DE =28.5 ($\because $ they are the opposite sides of the rectangle)
On putting the value of BC in (2) we get the equation as:
AB=(1)(28.5)=28.5
So, AB = 28.5
Height of the tower AD = 28.5 + 1.5 = 30 (From (1))
Hence, the height of the tower is 30 meters.
So, the correct option is B.
Note: In this type of problem students often make the mistake of excluding the height of the man in height of the tower.
Recently Updated Pages
Master Class 11 Economics: Engaging Questions & Answers for Success

Master Class 11 Accountancy: Engaging Questions & Answers for Success

Master Class 11 English: Engaging Questions & Answers for Success

Master Class 11 Social Science: Engaging Questions & Answers for Success

Master Class 11 Biology: Engaging Questions & Answers for Success

Master Class 11 Physics: Engaging Questions & Answers for Success

Trending doubts
Why is there a time difference of about 5 hours between class 10 social science CBSE

When and how did Canada eventually gain its independence class 10 social science CBSE

Fill the blanks with proper collective nouns 1 A of class 10 english CBSE

The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths

Write examples of herbivores carnivores and omnivo class 10 biology CBSE

10 examples of evaporation in daily life with explanations
