Answer: 
Step-by-step explanation:
Observe in the figure given in the exercise that four right triangles are formed.
In this case you can use the following Trigonometric Identity to solve this exercise:
From the figure you can identify that:

Then, you can substitute values:

The next step is to solve for DE in order to find its value. This is:

Finally, rounding the result to the nearest tenth, you get that this is:

Answer:
I think it is A.
Step-by-step explanation:
happy to help
Answer:
A. 2, 3, and 4
B: 4
Step-by-step explanation: