JAVA worksheet: rectangle, invariant line, stretch
Use the RESET button (top-right) to go back to START.
Use the RUN/PAUSE button (bottom-left) to RUN the animation.
When the animation has finished,
RESET, then DRAG point A or B or the whole invariant line to a new position, RUN the animation again;
OR: don't RESET but DRAG point A or B or the whole invariant line to a new position.
You can also move the blue rectangle, or change its shape by dragging point C.
Created with GeoGebra