Question

The picture shows a flagpole, AB, above a house
Rounded to the nearest whole number, what is the height, in feet, of the flagpole AB

Answer 1

height of the building is 17*tan45=17
let height if pole be X
tan60=(X+17)/17
X=[(sqrt3)-1]17
approx ....12.44
=12

Answer 2

wait can you like explain that to me?

Answer 3

well...height of building can be found out by using the tangent of the smaller angle......let height of building be Y.......tan45 is Y/17

Answer 4

tan45 is 1 so Y= 17

Answer 5

now height of building + height of pole is 17 + X....

Answer 6

so tan60 =(17 +X)/17
solve for X

Answer 7

how do you kno when to use tan? kus i didnt kno that i was suppose to use it

Answer 8

so im kinda confussed

Answer 9

tangent of an angle is used when we know either the side opposite to the angle or the side adjacent to it......so that other unknown quantity can be found out..

Answer 10

so whats x equal?

Answer 11

See, You need to find the height of the pole.. So, at first you need to find the height of the building.

The 'easiest' way to find is by using tan .. \[\tan \theta = \frac{adjacent}{opposite}\]

Let height of the building be "h"

\[Now, In.. that ... \triangle, \frac{h}{17} = \tan 45 = 1\]
\[=> h= 17 m\]
In that big triangle , the given angle = \[(45^o + 15^o) = 60^o\]
Now, \[\frac{AB + h}{17} = \tan 60^o = \sqrt3\]
\[=> AB + 17 = 17\sqrt3\]
\[=> AB = 17\sqrt3 - 17 = 17(\sqrt3-1) \]
\[= 17(0.735) \approx 12.46 \]

\[\therefore AB \approx 12.46 m\]

Answer 12

hey tangent = opposite /adjacent.....apart from dat everything else is rite

Answer 13

Oops! :P .. Silly mistake! :/

Answer 14

@bwish : Please don't mind that Tangent part .. My fault :/