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Homework Help: Solving Triangles. My answer fluctuates from the real answer

  1. Mar 27, 2015 #1
    Hey Guys. I'm having a bit of a problem with my solving triangles book. I'm finding the book really easy but there's this one thing that I keep getting wrong. Whenever I'm working with degrees with decimal points my answer aways fluctuates slightly from the real answer. I must be doing something wrong. Any help will be greatly appreciated!

  2. jcsd
  3. Mar 27, 2015 #2


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    I'm getting 8.62. Can you show me your input into your calculator? How are you expressing the minutes for example?
  4. Mar 27, 2015 #3


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    Actually, I see what you've done. You expressed [itex]65^o5'[/itex] as 65.5 in your calculator. This is not correct!


    because [itex]0.5^o[/itex] is half of a degree, and that is equal to 30' since [itex]60'=1^o[/itex].

    The opposite angle [itex]24^o55'[/itex] is NOT to be expressed as 24.55 in the calculator, but rather 24+55/60. Think about it in terms of time. The degree is the hour and the minute is the minute. What is 4 lots of 2 hours and 5 minutes equal to? Obviously it'll be 8 hours and 20 minutes. Let's check it though:

    It's not 2.5*3 = 7.5, but rather 2 hours * 3 + 5/60 hours * 3 = 6 hours + 15/60 hours = 6 hours and 15 minutes.

    This is what you want to put into your calculator:


    if your calculator is expressed in degrees.
  5. Mar 27, 2015 #4
    I did think maybe I'm calculating the minutes wrong but for the life of me I couldn't find anything on the internet about it.
  6. Mar 27, 2015 #5
    Oh I see now. Thank you for helping me! Finally I've been stuck here for a while now.
  7. Mar 27, 2015 #6


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    You're welcome!

    Also keep in mind that your calculator might also have a degrees, minutes and seconds button. You can use this button to easily express the degrees and minutes with [itex]65^o5^o[/itex] on the calculator, which would be equivalent to [itex]65^o5'=65+5/60[/itex]. Also, if you start using seconds too, then
    [tex]65^o5^o20^o[/tex] on your calculator would be equivalent to [tex]65^o5'20''=65+5/60+20/60^2=65+5/60+20/3600[/tex]
  8. Mar 27, 2015 #7


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    It's always going to be in the last place you look: :rolleyes:

  9. Mar 27, 2015 #8


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    Little details like that are what makes space probes fail to go into orbit around Mars.
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