Hi Chris, hi folks.
Another possibility is to do this for each triangle:
1 - Select all of it with a double click.
2 - Create component.
3 - While in the component creation window, click on Set component axes. Set the origin to some endpoint, the red axis along one edge and the green axis to be on the triangular face. This makes the blue axis perpendicular to the face of the triangle.
4 - When done, use the Component Browser to apply any of your triangle to any face, like a large rectangle created on the ground.
Once all that is done, explode the triangles components if required if you want their geometries to merge with the rectangle.
Just ideas.