We all think that AB>CD (distance between point A and B is much larger than distance between point C and D).
However, there are almost the same length!
Click play button to find out!

You can also use slider to adjust length (w) and angle (c).

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/illusion_samelength_pkg/illusion_samelength.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(751.6kB):double click downloaded file to run it. (14 times by 10 users) , Download EJS source (2 times by 1 users) View EJS source