Community Tip - You can subscribe to a forum, label or individual post and receive email notifications when someone posts a new topic or reply. Learn more! X
An intercept with lenght l = 4 moves so that its one endpoint moves along y-axis and the other endpoint - on the x-axis. Find image for curve, drawn by point C that is on the crossection of the intercept and its crossection from the origin of coordinate axis.
Maybe like this (click on the picture to start the animation):

Werner,
That was very good mathematical animation!
