For information about freeform shapes and editing points in shapes, see Draw or edit a freeform shape. On the Insert tab, click Shapes. Under Lines, click Curve. Click where you want the curve to start, drag to draw, and then click wherever you want to add a curve. To leave the shape open, double-click at any time. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.