About Imdistline() can't display the value of variable

With the imdistline(), i get the number of pixels between two points easily, i can also do some calculation, but i cant the display that calculation in the box on the line where it shows the pixles.

imshow('any image') F=3741; W=3.31; h = imdistline(gca); api = iptgetapi(h); pause('on'); pause; P = api.getDistance(); D=(W*F)/P; distance=D/12; % now how to display the distance variable value in the box, that's with the line