public void OnTriangleAdded(object sender, TriangleEventArgs args)
        {
            TriangleListItemViewModel viewModel = new TriangleListItemViewModel {
                Triangle = args.Triangle
            };

            TriangleListItems.Add(viewModel);
        }
        private ObservableCollection <TriangleListItemViewModel> CreateListViewModelsFromTriangeList(List <Triangle> triangles)
        {
            ObservableCollection <TriangleListItemViewModel> viewModels = new ObservableCollection <TriangleListItemViewModel>();

            foreach (var triangle in triangles)
            {
                TriangleListItemViewModel viewModel = new TriangleListItemViewModel {
                    Triangle = triangle
                };
                viewModels.Add(viewModel);
            }
            return(viewModels);
        }