Notifications
Clear all
From a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high building are 45° and 60° respectively. Find the height of the tower.
Applications of Trigonometry
1
Posts
2
Users
0
Likes
152
Views
0
17/06/2021 11:14 am
Topic starter
From a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high building are 45° and 60° respectively. Find the height of the tower.
Answer
Add a comment
Add a comment
Topic Tags
1 Answer
0
17/06/2021 11:15 am
Let BC be the 20 m high building.
Height of transmission tower = AB = AC – BC
AB, Height of the tower
From figure, In right ΔBCD,
tan 45° = \(\frac{BC}{CD}\)
1 = \(\frac{20}{CD}\)
CD = 20
In right ΔACD,
tan 60° = AC/CD
√3 = \(\frac{AC}{20}\)
AC = 20√3
AB = AC – BC = (20√3  20)
= 20(√3  1)
Height of transmission tower = 20(√3 – 1) m.
Add a comment
Add a comment
Forum Jump:
Related Topics

The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary.
1 year ago

A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of 30°, which is approaching the foot of the tower with a uniform speed.
1 year ago

A 1.2 m tall girl spots a balloon moving with the wind in a horizontal line at a height of 88.2 m from the ground. The angle of elevation of the balloon from the eyes of the girl at any instant is 60°.
1 year ago

As observed from the top of a 75 m high lighthouse from the sea level, the angles of depression of two ships are 30° and 45°.
1 year ago

From the top of a 7 m high building, the angle of elevation of the top of a cable tower is 60° and the angle of depression of its foot is 45°. Determine the height of the tower.
1 year ago
Forum Information
 321 Forums
 27.1 K Topics
 53.3 K Posts
 0 Online
 16.7 K Members
Our newest member: rachellebooze99
Forum Icons:
Forum contains no unread posts
Forum contains unread posts
Topic Icons:
Not Replied
Replied
Active
Hot
Sticky
Unapproved
Solved
Private
Closed
Super Globals
Requests: Array ( )
Server: Array ( )