Question

A 7 m long post supports a tree at a point 5m up the trunk. The post makes an angle of 45° with the ground. Calculate the angle the tree makes with the ground to the nearest degree

Answer 1

Answer:

Let A’CB be the tree before it broken at the point C and let the top A

′

touches the ground at A after it broke. Then ΔABC is a right angled triangle, at B.

AB=12 m and BC=5 m

Using Pythagoras theorem,

In ΔABC

(AC)

2

=(AB)

2

+(BC)

2

(AC)

2

=(12)

2

+(5)

2

(AC)

2

=144+25

(AC)

2

=169

AC=

169

AC=13 m

Hence, the total height of the tree(A

′

B) =A

′

C+CB=13+5=18m