This is a useful feature if the shape you are trying to create does not exist within the templates. It is also useful when attempting to dimension fillets at corners which cannot be done in the templates.
Example: Create a Points Shape
1) Expand the ‘Custom’ menu on the left, and click the ‘Add Points Shape’ button. An ambiguous, general looking shape will be drawn by default. Note the dashed line which draws the path of the points with no fillets.