coords

A set of values specifying the coordinates of the hot-spot region. The number and meaning of the values depend upon the value specified for the shape attribute. For a rect or rectangle shape, the coords value is two x,y pairs: left, top, right, and bottom. For a circle shape, the value is x,y,r where x,y is a pair specifying the center of the circle and r is a value for the radius. For a poly or polygon< shape, the value is a set of x,y pairs for each point in the polygon: x1,y1,x2,y2,x3,y3, and so on. In HTML4, the values are numbers of pixels or percentages, if a percent sign (%) is appended; in HTML5, the values are numbers of CSS pixels.