Question

from a point on the ground 48 feet from the foot of the tree, the angle of elevation of the top of a tree is 30 degree. find the height of the tree.​

Answer 1

Answer:

A bird is sitting on the top of a tree, which is 80m high. The angle of elevation of the bird, from a point on the ground is 45

∘

. The bird flies away from the point of observation horizontally and remains at a constant height. After 2 seconds, the angle of elevation of the bird from the point of observation becomes 30

∘

. Find the speed of flying of the bird (Take

3

=1.73 ).

Step-by-step explanation:

tan45

o

=

BC

AC

1=

BC

80

BC=80cm

tan30

o

=

BC+CE

DE

3

1

=

80+x

80

80+x=80

3

x=80

3

−80

x=80(

3

−1)m

The bird travelled 80(

3

−1)m

Speed of bird =

Time

Distance

=

2

40(

3

−1)

=40(

3

−1)m/s

∴ Speed =40(

3

−1)m/