The vertical angle to the top of a flagpole from point A on the ground is observed to be 37°11'. The observer walks 17 m directly away from point A and the flagpole to point B and finds the new angle to be 25°43'. What is the approximate height of the flagpole?

Respuesta :

Answer:

22m

Step-by-step explanation:

Let height of flagpole=h

AB==17 m

[tex]\angle CAD=37^{\circ}11'=37+\frac{11}{60}=37.183^{\circ}[/tex](1 degree= 60 minute)

[tex]\angle B=25^{\circ}43'=25+\frac{43}{60}=25.72^{\circ}[/tex]

We have to find the approximate height of the flagpole.

In triangle CDA,

[tex]\frac{CD}{DA}=tan\theta=\frac{Perpendicular\;side}{Base}[/tex]

[tex]\frac{h}{DA}=tan37.183^{\circ}[/tex]

[tex]h=DA(0.759)[/tex]

In triangle CDB,

[tex]tan 25.72^{\circ}=\frac{CD}{DB}[/tex]

[tex]0.482=\frac{h}{DA+17}[/tex]

[tex]0.482DA+8.194=h[/tex]

Substitute the value

[tex]0.482DA+8.194=0.759DA[/tex]

[tex]8.194=0.759DA-0.482DA[/tex]

[tex]8.194=0.277DA[/tex]

[tex]DA=\frac{8.194}{0.277}=29.58[/tex]

Substitute the value

[tex]h=29.58 \times 0.759=22.45 m\approx 22m[/tex]

Hence, the height of the flagpole=22 m

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