Step 1: Understand the given information and make an imaginary figure.

GIVEN: Assume a palm tree

Distance between the palm tree and observer = 13.2 m

Height of the observer = 1.8 m

Angle of elevation of the top of the tree from his eyes = 45\degree

FIGURE:

From the figure we can write

AC = BE = 13.2 m

AB = EC = 1.8 m

Step 2: Search for the suitable trigonometric ratio

NOTE: \triangle BDE is right angle triangle

We know the adjacent side we have to calculate the opposite side

So, use the \tan \theta = \frac{opposite}{adjacent}

EXAMPLE: \tan \theta = \frac{opposite}{adjacent} =\frac{DE}{BE}

\tan 45\degree = \frac{DE}{13.2} (BE = AC)

DE = 13.2 m

Total length of the palm tree = EC + DE

= 1.8 + 13.2 (since, AB = EC)

= 15 m