Question

A vertical flagstaff stands on a horizontal plane. From a point 100 m from its foot, the angle of elevation of its top is found to be 45°.Find the height of the flagstaff.

Answer 1

LINE OF SIGHT: The line of sight is a line drawn from the eye of an observer to the point in the object viewed by the observer.

ANGLE OF ELEVATION: The angle of elevation of an object viewed is the angle formed by the line of sight with the horizontal , when it is above the horizontal level.

ANGLE OF DEPRESSION:The angle of depression of an object viewed is the angle formed by the line of sight with the horizontal , when it is below the horizontal level.

•Angle of elevation and depression are always acute angles.

•If the observer moves towards the perpendicular line(Tower/ building) then angle of elevation increases and if the observer move away from the perpendicular line(Tower/ building) angle of elevation decreases.

SOLUTION:

Given:
∠BAC = 45° (angle of elevation)
AB = 100 m be distance of a flagstaff from its foot on a horizontal plane.

BC = h m be the height of the flagstaff.

In ∆ABC ,
tan 45° = BC / AB = P/ B
1 = h / 100
h = 100 m

Hence, the height of the flagstaff is 100 m.

HOPE THIS WILL HELP YOU...

Answer 2

Hey!!

Here is your answer,,

Height of a flagstaff (AB) = h m

BC = 100m

Angle of elevation = 45°

Tan 45 = P/b

1 = AB/BC

1 = h/100

h = 100

Height of a flagstaff is 100m.


Hope it helps ....

THANKS...
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