Trig help: height at top of ladder, depth of submarine, etc

[Samara]

I have five problems that I have completed and I was wondering if someone might be able to check my work? I am also unsure of how to put number 20 in my calculator...

 

[Samara]

for number 20, I get 83.169
I do not know if I did this correctly or not?

 

[Deleted member 4993]

for number 20, I get 83.169
I do not know if I did this correctly or not?

height of flagpole = 100*(tan39°45' - tan28°)

 

[Samara]

I now get 29.998

 

[Deleted member 4993]

The answer should be 30 ft. You got it.

 

[Samara]

Thank you very much for all of your help!