getlineinfo draws a line using the pointer, and displays the length and 
angle of the segment in the figure. The angle is in degrees by default, 
(zero angle for a horizontal line). 
 
[LEN, ANGLE, DX, DY] = getlineinfo returns the results. 
 
... = getlineinfo(OPT) specifies the angle property: OPT = 'rad', 'deg' 
or 'slope' (default is 'deg').  OPT = 'angle' shows only the angle. 
 
Note: The Image Processing Toolbox is required. 
 

getslope. 
 
Published output in the Help browser 
   showdemo getlineinfo