Asked by zainab
2. A person walking along a straight road observed that at two consecutive kilometre stones the angles of elevation of a hill front of him are 40o and 80o respectively. Find the height of the hill.
Answers
Answered by
Reiny
Make a sketch
I have A, B, and C on a horizontal line, and H as the top of the hill
Angle A = 40° and angle HBC - 80°, AB = 2 km
In triangle ABH, angle ABH = 100°
then angle AHB = 40°
which makes BH = 2 , (isosceles triangle)
(that was lucky, else I would need the sine law to find BH)
in triangle HBC (right-angled)
sin 80 = HC/2
HC = 2sin80 = 1.97 km
Wow, that is more than just a "hill"
I have A, B, and C on a horizontal line, and H as the top of the hill
Angle A = 40° and angle HBC - 80°, AB = 2 km
In triangle ABH, angle ABH = 100°
then angle AHB = 40°
which makes BH = 2 , (isosceles triangle)
(that was lucky, else I would need the sine law to find BH)
in triangle HBC (right-angled)
sin 80 = HC/2
HC = 2sin80 = 1.97 km
Wow, that is more than just a "hill"
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.