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Homework Help: Finding radius of circle inscribed in a triangle

  1. Sep 19, 2010 #1
    1. The problem statement, all variables and given/known data

    Someone gave me this problem: finding the radius of the circle inscribed in the triangle with the given lengths.


    3. The attempt at a solution

    The person asking about this problem said it was taken from a beginning algebra textbook. I tried figuring it out using just basic algebra, but I couldn't make any progress. Is this problem solvable with basic algebra/geometry? Would it be any easier if it were a right triangle?
  2. jcsd
  3. Sep 19, 2010 #2


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    Homework Helper

    What I can deduce that you must use are some of the circle theorems, such as the angle made by a tangent and radius at the point of contact is 90°, as well as possibly some trigonometry.

    I believe that the two tangents that meet (made by the 4 unit and 3 unit line) are both equal by one of the circle theorems.
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