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

b1gd0g

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?

mathman

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.

b1gd0g

Thanks mathman. I just needed a little insight, and you have provided that quickly and succinctly.

Similar Threads for: Find the coordinates of a point on a circle without knowing the center point.
Thread	Forum	Replies
Coordinates of a random point of a circle?	General Math	18
Please help to Find coordinates of a point formula Angle,Distance & first point known	Differential Geometry	3
Finding coordinates of a point in a circle with angle	General Math	5
Calculating point X on the Golden Spiral knowing a point and a distance	Calculus	0

mathman Recognitions: 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.

b1gd0g	Thanks mathman. I just needed a little insight, and you have provided that quickly and succinctly.