See complete Problem 71
Cyclic Quadrilateral, Angles. Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Monday, May 19, 2008
Elearn Geometry Problem 71
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See complete Problem 71
Cyclic Quadrilateral, Angles. Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
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.
ReplyDeleteCan anyone tell me if this is right?
Yes, it is right. Q.E.D.
ReplyDeleteVideo-solution
ReplyDeletehttp://www.youtube.com/watch?v=D-DFhH8XYgM
Note that the reciprocal is true.
β+∡BCD=180°
ReplyDeleteβ=180°-∡BCD
α+∡BCD=180°
α=180°-∡BCD
α=β
β+∡BCD=180°
ReplyDeleteβ=180°-∡BCD
α+∡BCD=180°
α=180°-∡BCD
α=β