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

Here, AB is the light house and CD is the observer, Rodney.
The angle of elevation is represented by
ADE.

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
Concept Videos
CBSE 10 - Maths
Asked by shanbhog.06 | 14 Apr, 2022, 11:26: AM
CBSE 10 - Maths
Asked by godboletanaya | 24 Dec, 2021, 11:08: AM
CBSE 10 - Maths
Asked by nikunjgupta102021 | 12 Jul, 2021, 09:01: AM
CBSE 10 - Maths
Asked by onkarmishra074 | 17 May, 2020, 14:52: PM
CBSE 10 - Maths
Asked by udaya2885 | 04 Jan, 2020, 22:45: PM
CBSE 10 - Maths
Asked by Topperlearning User | 02 Nov, 2017, 09:19: AM
CBSE 10 - Maths
Asked by Topperlearning User | 02 Nov, 2017, 09:26: AM
CBSE 10 - Maths
Asked by Topperlearning User | 02 Nov, 2017, 09:34: AM
CBSE 10 - Maths
Asked by Topperlearning User | 02 Nov, 2017, 09:36: AM
CBSE 10 - Maths
Asked by Topperlearning User | 02 Nov, 2017, 09:46: AM