Monday, June 9, 2008

Elearn Geometry Problem 117



See complete Problem 117
Area of Triangles, Incenter, Excircles, Tangent. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

2 comments:

  1. name M point P meet AB, T meet AC
    name N point Q meet BC, S meet AC

    from P119

    S2 = SHIN, S3 = SGIM

    have to prove SINC = SIMA or
    NC = AM*, because altitude is r for two tr

    AS = AE (as tg from A )
    AC + CN = AB + BN ( CN=CS ,BE=BN, tg from C, B )
    AC + CN = AM + MB + BC - CN ( AB = AM+MB, BN = BC-CN)
    AC + CN = AM + AC + AM - CN ( MB+BC = AC+AM = 1/2p )
    2∙CN = 2∙AM

    CN = AM*
    -----------------------------------------

    ReplyDelete
  2. (area of IAE) = (area of ICD)= (1/2)(area of ABC).
    Subtract (area of IGBH) from both sides.

    ReplyDelete