You can use the Pleats/Darts feature to add a diamond dart to your garment.
To add a diamond dart:
On the Main toolbar, click Insert.
On the Horizontal contextual menu, click .
Click Diamond Dart.
In the 2D window, drag inside the piece where you want the dart to be. A diamond dart is displayed.
Edit the dart as required:
On the Horizontal contextual menu, ensure Edit Points is selected.
In the 2D window:
Drag to move the top or bottom of the dart.
Drag to widen or narrow the dart.
For precise sizing, click the dart, and go to the Context view. Edit the Width and Height values as required..
Drag the dart to move it to a new location. For precise positioning, click the dart, and go to the Context view. Edit the X and Y values as required.
Save the file: on the Main toolbar, click .