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Homework Help: Find the length of the adjacent

  1. Jan 10, 2010 #1
    I have been practising trig on the bb bitesize maths website. It keeps telling me that I have given the wrong answer to the following problem.
    Draw a triangle XYZ with Y being a right angle. The angle at X is 42 degrees and the length of YZ is 3.7cm.
    The question requires you to find the length of XY (the adjacent side) to 3 s.f.
    I did the calculation tan42 = 3.7/XY and came up with a length of 4.11cm. I also tried 4.10cm (without rounding up), but according to the website both answers are wrong.
    Can anyone tell me where I am going wrong?
  2. jcsd
  3. Jan 10, 2010 #2


    Staff: Mentor

    It could be that the website is looking for an answer with three significant decimal places, which would be 4.109. My calculator gives the length of the adjacent side as 4.109266305 (cm). To 3 significant figures, this would be 4.11 cm.
  4. Jan 11, 2010 #3
    Thanks a lot Mark. As long as I know I did the right calulation I'm happy!
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