$\"\"$

Height of the building is $\"\"$ .

Height of the shadow is $\"\"$ .

$\"\"$

Let $\"\"$ the height of the building $\"\"$ , and $\"\"$ is the height of the shadow $\"\"$ .

Observe the figure :

$\"\"$

Therefore, the angle of elevation of the sun is $\"\"$ .

$\"\"$

The angle of elevation of the sun is $\"\"$ .