Answer: 

Explanation:
 Draw a right triangle where "x" is the height in meters of the tent (Observe the picture attached).
 You need to use the following Trigonometric Identity:
 

 In this case, you can identify that:
 

 Now you must substitute these values into 
. Then:
 

 Finally you must solve for "x" in order to find its value.
 This is:
 
