Find the height of the tree. If a tree breaks due to a storm and the broken part bends in such a way the top of the tree touches the ground making an angle 45° with the ground and the distance between the foot of the tree to where the top touches the ground is 20 m.
Find the height of the tree. If a tree breaks due to a storm and the broken part bends in such a way the top of the tree touches the ground making an angle 45° with the ground and the distance between the foot of the tree to where the top touches the ground is 20 m. Correct Answer 20(1 + √2) m
From the figure,
Height of the Tree = BC + BD
In triangle BCD
⇒ tan 45° = Perpendicular/Base = BC/CD
⇒ tan 4
5° = BC/20
⇒ BC = 20
We use Pythagoras theorem,
⇒ BD2 = BC2 + CD2
⇒ BD2 = 202 + 202
⇒ BD = 20√2
∴ Height of the tree = 20 + 20√2 = 20(1 + √2) m
Alternate solution:
[ alt="F1 Sachin.T 19-05-2020 Savita D5" src="//storage.googleapis.com/tb-img/production/20/05/F1_Sachin.T_19-05-2020_Savita_D5.png" style="width: 485px; height: 186px;">
From the figure,
Height of the tree = x + √2x
⇒ x = 20
⇒ √2x = 20√2
∴ Height of the tree = 20(1 + √2) m