1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Radians circles

  1. Feb 16, 2012 #1

    for part b i'm not sure how to do it

    any hints on how to do it? Ive tried using sine rule etc but i'm just guessing, and i'm pretty sure there is a more simple method.
  2. jcsd
  3. Feb 16, 2012 #2
    Re: Radians/circles

    Hint: What is the relation between the angles DAB and DAC?
  4. Feb 16, 2012 #3
    Re: Radians/circles

    Right well I got this, i'm not sure if its right. DAB and DAC are equal so lets call DAB "a", 2pi = 2.2 + 2a so 2pi - 2.2 / 2 = a which is pi - 1.1 = 2.04?
  5. Feb 16, 2012 #4
    Re: Radians/circles

    That's right, and I believe your math is correct too.

    Since all three sides of the triangles are congruent:
    [itex]\overline{DB}\cong\overline{DC}[/itex] given
    [itex]\overline{BA}\cong\overline{AC}[/itex] because they are the same length
    [itex]\overline{AD}\cong\overline{AD}[/itex] trivial, they share a common line
    Then the corresponding angles in the triangles must also be congruent.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook