The two palm trees are of equal heights and are standing opposite each
other on either side of the river, which is 80 m wide. From a point O
between them on the river the angles of elevation of the top of the trees
are 60° and 30°, respectively. Find the height of the trees and the
distances of the point O from the trees.
Need urgently no rubish answer required
Answers
Answer:
Let BD=river
AB=CD=palm trees=h
BO=x
OD=80-x
In ∆ABO,
Tan60˚=h/x
√3=h/x -----------------------(1)
H=√3x
In ∆CDO,
Tan 30˚=h/(80-x)
1/√3= h/(80-x) ---------------------(2)
Solving (1) and (2), we get
X=20
H=√3x=34.6
the height of the trees=h=34.6m
BO=x=20m
DO=80-x=80-20=60m
Given:
Distance between two trees=80m
To find:
i. The height of the trees
ii. The distance of point O from the trees
Solution:
The height of the trees is 20 m and the distance of point O from the trees is 60 m and 20 m.
We can find the solution by following the given steps-
We know that the height and distance can be calculated by using trigonometry.
Let the height of the trees be H and the distance from O to one of the trees is D.
The distance between O and the other tree=(80-D)
Now, point O is making an angle of 30° and 60° with each tree.
Tan theta=Perpendicular/Base
So, tan 30°=H/D
=H/D
D/=H (1)
Similarly, tan 60°=H/(80-D)
=H/(80-D)
(80-D)=H
From (1),
(80-D)=D/
3(80-D)=D
240-3D=D
240=4D
D=60 m
The distance between O and other tree=(80-D)=80-60=20m
So, H=60/
H=20 m
Therefore, the height of the trees is 20 m and the distance of point O from the trees is 60 m and 20 m.