Tuesday, February 3, 2009

Elearn Geometry Problem 242: Triangle with Equilateral triangles, Parallelogram

Problem: Triangle with Equilateral triangles, Parallelogram

See complete Problem 242 at:
gogeometry.com/problem/p242_triangle_equilateral_parallelogram.htm

Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

2 comments:

  1. C'A = BA
    angle C'AB' = Angle BAC = 60 - angle B'AB
    AB' = AC
    So, by SAS postulate,
    triangle C'AB' is congruent to triangle BAC
    So, C'B' = BC = BA'
    Similarly as
    triangle A'B'C is congruent to triangle BAC,
    A'B' = BA = BC'

    So,
    in quadrilateral A'BC'B' both pairs of opposite sides are congruent.
    So, it is a parallelogram.

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  2. http://img15.imageshack.us/img15/857/problem242a.png

    ReplyDelete