Monday, May 19, 2008

Elearn Geometry Problem 71



See complete Problem 71
Cyclic Quadrilateral, Angles. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

5 comments:

  1. ABCD is a cyclic quadrilateral therefore angle beta and angle BCD are supplimentary. So beta + BCD = 180 degrees. Also, alpha + angle BCD = 180 degrees because they lie on a straight line. therefore alpha equals beta.

    Can anyone tell me if this is right?

    ReplyDelete
  2. Video-solution

    http://www.youtube.com/watch?v=D-DFhH8XYgM

    Note that the reciprocal is true.

    ReplyDelete
  3. β+∡BCD=180°
    β=180°-∡BCD
    α+∡BCD=180°
    α=180°-∡BCD
    α=β

    ReplyDelete
  4. β+∡BCD=180°
    β=180°-∡BCD
    α+∡BCD=180°
    α=180°-∡BCD
    α=β

    ReplyDelete