Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 10 Answered

Rodney stood 30 m away from the light house in such a way that the angle of elevation of the top of the light house from his eyes was 45º. Rodney"s height is  1.4 m. Find the height of the light house.
Asked by Topperlearning User | 02 Nov, 2017, 09:36: AM
Expert Answer
Here, AB is the light house and CD is the observer, Rodney.
The angle of elevation is represented by angleADE.
Hence, we can see that in this case, ADE is a triangle, right angled at E and we are required to find out the height of the light house.
We have       AB = AE + BE
                     AB = AE + 1.4
And              DE = CB = 30 m
Now, to determine AE, we choose a trigonometric ratio that involves both AE and DE.
Let us choose the tangent of the angle of elevation.
So, the height of the light house (AB) = (30 + 1.4) m = 31.4 m
Answered by | 02 Nov, 2017, 11:36: AM
CBSE 10 - Maths
Asked by nikunjgupta102021 | 12 Jul, 2021, 09:01: AM
CBSE 10 - Maths
Asked by onkarmishra074 | 17 May, 2020, 02:52: PM