Point of confusion: In Case I, when calculating the internal work done, we would determine the length of the yield line and when calculating the external work done, we would find the length about which the rigid body rotates. In this case (Case IV), we seem to be taking the length about which the rigid body rotates for both internal work and external work. There seems to be an inconsistency. Kindly assist.

for IDW why the work done by center line and inclined line is ignored ??

Can you pl make the video for continuous support type case!!