1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Geometrical (circle) Proofs - Help!

  1. Nov 17, 2012 #1
    Two circles intersect at P and Q. Two parallel line segments APC and BQD are drawn to meet one circle at A and C, and the other circle at B and D. PB and PD are diameters of their respective circles. Prove that points B, Q and D are collinear.

    AB and CD are two parallel chords of a circle. If two other chords BF and DE are drawn such that they are parallel, prove that AE is parallel to CF.

    For the first question, I'm not even sure how to draw it, as I don't see how A and C could be point on the same circle if the line goes through APC. I also don't understand why it's asking to prove BQD is collinear if it has already said that BQD is a (straight) line segment.

    I've drawn a diagram for Q2, but I find that it's difficult to always know where to start with proofs. Any help would be much appreciated :)
  2. jcsd
  3. Nov 18, 2012 #2


    User Avatar

    Staff: Mentor

    Hi robobuggg, http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

    I agree, Q(1) doesn't make sense.
    Last edited by a moderator: May 6, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Geometrical circle Proofs Date
Geometric locus Jun 16, 2017
Geometric interpretation of complex equation May 9, 2017
Values of x for which a geometric series converges Apr 6, 2017
Geometrical properties of circle Dec 23, 2014