Question
From the top of a lighthouse, the angle of depression to
the top and bottom of a tower is 30° and 45°, respectively. If the lighthouse is 210 metres high, then find the height of the tower.Solution
Let AB and CD be the heights of the light house and the tower, respectively So, AB = 210 metres, ∠ ADE = 30° and ∠ ACB = 45° Now, in right angled triangle ABC tan45° = AB/BC So, AB/BC = 1 Or, AB = BC So, BC = 210 metres And, BC = DE = 210 metres So, in right angled triangle AED, tan30° = AE/DE Or, AE = 210 × (1/√3) Or, AE = 70√3 Also, CD = BE So, height of tower CD = AB – AE = 210 – 70√3 = 70√3(√3 – 1) metres
Which platform was allowed to extend UPI services to its entire user base in India by NPCI?
Prime Minister Narendra Modi recently inaugurated the Banjara Virasat Museum in which Indian state?
As per the Union Budget of 2021-22, how many regional national institutes of virology will be set up?
After the March 2026 amendment, into how many categories has the framework for achieving 25% Minimum Public Shareholding been expanded?
- Madhya Pradesh now has how many tiger reserves including Madhav National Park?
Titagarh Naval Systems launched the 4th Diving Support Craft (DSC A23) for the Indian Navy. On which river was the vessel launched?
Which individual received a six-month extension as MD & CEO of Yes Bank starting October 6, 2025?
The Paramakudi–Ramanathapuram four-laning project is being developed on which National Highway?
As per the government, which among the following is the loss making insurance company in the year 2021?
Which University to be declared as the World’s First Living Heritage University by UNESCO?
Relevant for Exams:
