After the preparation of the Model on screen, you need to do some corrections on the Nodes that have been generated.
For example you may want to:
•Move Nodes to their exact positions, if needed.
•Define or change Nodal Constraints (Supports).
•Define Springs, if needed.
Click 
to edit Nodes. For details, see Nodes.
We get the Nodes form as follows:
We see that the Y coordinate of nodes B and C is 2.6 [m], which needs to be corrected to the right value, 2.598076211 [m]. We click on the two cells and we correct the value. Then the table should look like this:
What we need to do is to add Constraints (Supports) to the Model. Set the Constraints for Nodes A and B to "pinned", as follows:
Then Click OK. The Model should now look like this:
The supports have been added to Nodes A and C as shown above, and Nodes B and C are now in their correct locations.