Draw a shape in Keynote on Mac
You can create your own freehand shapes.
Go to the Keynote app
on your Mac.Open a presentation, click
in the toolbar, then click 
.Click anywhere on the slide (or its surrounding workspace) to create the first point of the custom shape.
Move the pointer, then click to create another point; continue adding as many points as you want.
To create a curved segment, click then drag, then click again to finish the segment.
To delete a segment you just created, click a point to select it, then press the Delete key.
To complete the drawing, do one of the following:
Close the shape (add a solid line between the last and first points): Click the first point.
Leave the shape open (add no line between the last and first points): Press Return or Esc.
To modify the points or line contours of the shape, click the shape to select it, then choose Format > Shapes and Lines > Make Editable (from the Format menu at the top of your screen).