2010 · Q2
What is the locus of centres of circles which touch a given line at a given point ?
Elementary MathematicsGeometry
- AA line perpendicular to the given line, passing through the given point
- BA line parallel to the given line
- CA circle tangent to the given line at the given point
- DA closed curve other than a circle
Explanation
The centre must lie on the line through the point perpendicular to the given line (radius can vary).