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: 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


    User Avatar
    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook