this works when it is not close to noon
put the yardstick next to the pole
measure the shadow of the pole, call it x
measure the letngh of the shadow of the yardstick
measure the height of the yardstick
the ratio of the height of the yardstick to the shadow of the yardstick should be close to the ratio of the height of the pole to the legnth of the shadow of the pole