A rule is easy to only measure the height of a tree using.

What is needed for this experiment?

  • A rule of 30 cm
  • What is necessary to do?

    To measure the height of a tree, a building or any other object is relatively simple if it is had a rule. The procedure is the following one:

  • 1. To be placed to a well-known distance of the object whose height H is wanted to measure, in this case the tree. We call D to that distance.
  • 2. To extend the arm while a rule around the eyes is maintained vertically. We call d to the distance between the hand and the eye.
  • 3. To close one of the eyes and with the rest to determine to whichever centimeters of the rule corresponds the height of the tree. To that length measured in the rule we denominated it h.
  • What is necessary to do?

    By similarity of triangles it is obtained that H/h = D/d. From this relation it is obtained that the height of the tree is:

    H = h. (D/d)


    As example we suppose that the distance that separates to us of the tree is of 50 meters, that our extended arm measures 60cm (0.6m) and that in the rule we saw that the relative height of the tree is of 20cm (0.2m), therefore the true altitude of the tree will be:

    H = (0,2 x 50/0,6) m = 16.6m