Monday, September 22, 2008

Elearn Geometry Problem 181

Circular sector of 90 degrees

See complete Problem 181 at:
www.gogeometry.com/problem/p181_circular_sector_90_angle.htm

Circular Sector of 90 degrees, find an angle. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

6 comments:

  1. x=(360°-90°)/2=135°

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  2. http://mate-facil.co.cc/go-geometry-181/
    By TiNo

    ReplyDelete
  3. let us draw the complete circle, then the chord AB will subtend an angle equal to (1/2)*90 = 45 degrees on the major arc. let one such point be D then ACBD form a cyclic quadrilateral with angles ACB and ADB being supplementary. so angle ACB = 180-45 = 135 degrees.

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  4. http://img31.imageshack.us/img31/1804/problema181resuelto.png

    Greetings ^^

    ReplyDelete
  5. Three solutions :)

    http://youtu.be/Djygod0XGdk


    Greetings ^^

    ReplyDelete
  6. Join OC
    Let <COB=2y
    OC=OB
    <OCB=90-y
    <AOC=90-2y
    OC=OA
    <OCA=45+y
    x=<OCB+<OCA=135

    ReplyDelete