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!

Find the coordinates of a point on a circle without knowing the center point.

  1. Sep 9, 2011 #1
    Given 2 points on a circle, call them A and B. I know the cartesian coordinates of A. I also know the radius of the circle, the slope of the tangent line at A, and the length and direction of the arc between A and B. I don't know the coordiates of the center of the circle.

    How do I find the coordinates of point B?
  2. jcsd
  3. Sep 9, 2011 #2


    User Avatar
    Science Advisor

    The radius at A is perpendicular to the tangent line. The center is along the radius at a known distance. There are only two possible points. Use the information about B (direction of arc??) to choose the location of the center.
  4. Sep 9, 2011 #3
    Thanks mathman. I just needed a little insight, and you have provided that quickly and succinctly.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook