From the top of a building 60m high, the angle of elevation and depression of the top and the foot of another building are α and β respectively. Find the height of the second building.
Answers
Step-by-step explanation:
Let the line segment AB represents the height of the lamp ( where A is the top of the lamp ), ED represents the height of the building,
While C is any point on ED such that CA ║ DB and CA = DB
Thus, by the below diagram,
In triangle ECA,
Now, in triangle EDB,
Thus,
√3 EC = 60 / √3
⇒ 3 EC = 60 ⇒ EC = 20
Since, AB = CD = ED - EC = 60 - 20 = 40 meters,
Hence, the height of the lamp post is 40 meters.
Answer:
Let the line segment AB represents the height of the lamp ( where A is the top of the lamp ), ED represents the height of the building,
While C is any point on ED such that CA ║ DB and CA = DB
Thus, by the below diagram,
In triangle ECA,
tan 30^{\circ}=\frac{EC}{CA}
Now, in triangle EDB,
Thus,
√3 EC = 60 / √3
⇒ 3 EC = 60 ⇒ EC = 20
Since, AB = CD = ED - EC = 60 - 20 = 40 meters,
Hence, the height of the lamp post is 40 meters.