Answer:
Height of the tree, h = 20.72 meters
Step-by-step explanation:
Given that,
The sun is 21° above the horizontal,
![\theta=21^(\circ)](https://img.qammunity.org/2020/formulas/physics/college/j6ndsw19nm5gkvsj2yphqg5zygfwp9m2pi.png)
Length of the shadow, d = 54 m
Let h is the height of the tree. It can be calculated using trigonometry as :
![tan\theta=(perpendicular)/(base)](https://img.qammunity.org/2020/formulas/physics/college/ymwi7jqcsa6m2bu60b6d4cihuw1v2s9xlo.png)
Here, perpendicular is h and base is 54 meters.
![tan(21)=(h)/(54)](https://img.qammunity.org/2020/formulas/physics/college/wmu1v798vxx660vgapun0b5wxgmkbi4ern.png)
![h=tan(21)* 54](https://img.qammunity.org/2020/formulas/physics/college/gt40i7ui0xquwaesewicr1rbhvqty7ld60.png)
h = 20.72 meters
So, the height of the tree is 20.72 meters. Hence, this is the required solution.