Question

40. A 1.5 m tall boy standing at a some distance from a 30m tall building. The
angle of the elevation from his eyes to the top of the building increases from
30° to 60° as he walks towards building. Find the distance he walked towards
the building
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Answer 1

Answer:

AB= 30-1.5=28.5 cm

In ΔABD:−tan30∘=BDAB

⇒BD=(28.5)3

In ΔABC:−tan60∘=BCAB

⇒BC=3(28.5)

CD= BD-BC

=28.5(3−31)

=28.5(32)=32.91m