Question

BC is a tower, B is its base. A is a point on a horizontal line passing through B, the
angle of elevetion of C from A is 60° From another point Don AB, the angle of
elevation is found to be 30°, then BD=​​

Answer 1

Hope ,this might help you.

Answer 2

Given :-

• BC is a tower with B is its base. = Let height = h units.
• A is a point on a horizontal line passing through B.
• The angle of elevetion of C from A is 60° = ∠CAB.
• From another point D on AB, the angle of elevation is found to be 30° = ∠CDB .

To Find :-

• BD = ?

Solution :-

in Right ∆CBA ,

→ Tan60° = Perpendicular / Base

→ Tan60° = h / BA

→ √3 = h/BA

→ h = √3BA . ----------- (1)

Similarly,

→ in Right ∆CBD ,

→ Tan30° = Perpendicular / Base

→ Tan30° = h / BD

→ (1/√3) = h/BD

→ √3h = BD .

→ h = (BD/√3). -------------- (2)

From (1) and (2) , we get,

→ (BD/√3) = √3BA

→ BD = √3 * (√3BA)

→ BD = 3BA. (Ans.)

Hence, Length of BD is 3 times to the Length BA.