Question

A 7m long flagstaff is fixed on the top of a tower standing on the horizontal plane.From a point on the ground the angle of elevation of the top and bottom of the flagstaff are 60 and 45 respectively.Find the height of the tower correct to the place of decimal.

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

Height of tower is 9.6 m

Step-by-step explanation:

Given: Height of flagstaff = 7 cm

           Angle of elevation of the top of flagstaff = 60°

           Angle of elevation of the bottom of flagstaff = 45°

To find: Height of Tower

Figure is attached.

Let, CB be the height of tower

In Δ CDB,

using Trigonometric Ratio we get,

$tan\,45=\frac{CB}{CD}$

$1=\frac{CB}{CD}$

$CD=CB$

In Δ ACD,

using Trigonometric Ratio we get,

$tan\,60=\frac{CB+7}{CD}$

$\sqrt{3}=\frac{CB+7}{CB}$

$\sqrt{3}CB=CB+7$

$(\sqrt{3}-1)CB=7$

$CB=\frac{7}{\sqrt{3}-1}$

$CB=9.6$

Therefore, Height of tower is 9.6 m