In my program I'm taking the centre co-ordinates and the radius from the user ..now how can I use this information to draw a circle. The ellipse function takes four co-ordinates ..how do I use the ellipse to draw the circle and also how can I determine if the given co-ordinates lie inside the cirlce.

If you know how to draw an ellipse with a given center and width and height, consider that a circle is an ellipse whose width and height are equal to the diameter of the circle.

So, for example, with the Windows GDI Ellipse() function, if the center coordinates are (cx, cy) and the handle is hDC, then draw a circle with a given radius with:



Given a circle with center at coordinates (cx,cy), and given a point with coordinates (x,y): If the distance from (x,y) to (cx,cy) is less than the radius, the point is inside the circle.

Regards,

Dave