shape [HTML4 only] [Obsolete since HTML5]

This attribute is used to define a selectable region for hypertext source links associated with a figure to create an image map. The values for the attribute are circle, default, polygon, and rect. The format of the coords attribute depends on the value of shape. For circle, the value is x,y,r where x and y are the pixel coordinates for the center of the circle and r is the radius value in pixels. For rect, the coords attribute should be x,y,w,h. The x,y values define the upper-left-hand corner of the rectangle, while w and h define the width and height respectively. A value of polygon for shape requires x1,y1,x2,y2,... values for coords. Each of the x,y pairs defines a point in the polygon, with successive points being joined by straight lines and the last point joined to the first. The value default for shape requires that the entire enclosed area, typically an image, be used.

Note: 
It is advisable to use the usemap attribute for the <img> element and the associated <map> element to define hotspots instead of the shape attribute.
