Tuesday, October 21, 2008

Elearn Geometry Problem 194

Area of a Triangle, Semiperimeter, Exradius

See complete Problem 194 at:
www.gogeometry.com/problem/p194_area_of_a_triangle_semiperimeter_exradius.htm

Area of a Triangle, Semiperimeter, Exradius. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

3 comments:

  1. Hints:
    Area ABC = Area ABE + Area ACE - Area BCE.
    Apply Area of a triangle = bh/2 three times.

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  2. Let the perpendicular from E_a meet AC extended in M and from E_a to BC in N. We know that AM = s. Therefore Tr. ABC = s*r_a - (CN*r_a+BN*r_a)
    = s*r_a - (CN+BN)*r_a
    = s*r_a - BC * r_a
    =(s-a)r_a
    Ajit: ajitathle@gmail.com

    ReplyDelete
  3. I was wondering if somone could give more detail on either of these proofs. thanksssss

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