Dynamic Block - Triangle

[Mike_Taylor]

So, for the OP.

 

As long as the action box , the bos you make for your stretch action, encompasses all items you are hoping to move, the example i posted will work.

 

As you can see in the block editor, I have one linear parameter (dimension) on each side. The one with the drag grip has a scale feature on linear parameter on the other side. It also stretches the features on its own side. Iin my example the action grip is on the left so, so the linear perameter on the left scales the one on the right as well as stretches the member connecting the parts at the end as well as moving all the parts. The linear parameter on the left has the same stretch on the parts and member on its corresponding side.

 

Essentially your stretch one side, scaling the other linear parameter which in turn stretches its side.

 

Note:

1. Make sure both paramaters are parallel to the member you want getting longer.
   
2. Both paramters must have the chain actions option in the properties on.
   
3. The stretch action will MOVE all objects it full encompasses. It will STRETCH any object it does not ecompass with all points outside the box remaining static.