Question

plz solve this?????​

Answer 1



Primary School

Math

5 points

A 1.5 m tall boy is standing at some distance from a 30 m tall building.The angle of elevation from his eyes to the top of the building increases from 30° to 60° as he waljs towatds the building.Find the distance he walked towards the building

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 by Raviji1 25.01.2017

plz tell me 



do u want the whole solution or only answer 

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Answers



Priyanshi121 

Ambitious

Let AB=CD= EQ = 1.5 m

Let dist. covered by boy is BD=x

Let BD=AC=x

Let DQ=CE=y

In fig. PE=30-1.5=28.5m

Angles are 30° and 60°

In ∆ PAE 

tan 30 = PE/AE

1/√3=28.5/x+y 

28.5√3=x+y –(1)

In ∆PCE

tan60=PE/CE

√3=28.5/y

y=28.5/√3

Put in (1)

x+28.5/√3=28.5√4

x=(28.5×3-28.5)/√3

= (85.5-28.5)/√3

=57/√3

Rationalize

=57/√3×√3/√3

=57√3/3

=19√3