The goal is to use a North American First Nations technique to derive the height of tall objects, such as trees. It works like this. All sides of a square are equal in length. There are 4 x 90 degree angles in a square. If we bisect a square from corner to opposite corner, we are left with a triangle with 2 x 45 degree angles and 1 x 90 degree angle.
The height and base of this triangle derived from the square are the same. Therefore, so long as we have a way of finding 45 degree of angle and can measure to the base of the object in question, we can then calculate the height of the object through creating a 45/45/90 degree triangle. So, how does one make a 45 degree angle without tools? This is the fun part! If you bend over and look through your legs, you can create a 45 degree angle. It might take some calibration with objects you can actually measure by hand to get your positioning correct. However, once you have your technique down, you can apply it to any tall object outside! The trick is to bend over and look through your legs so that you can just see the top of the object in question. If you do that correctly, you should be at about 45 degrees. How to find the height of a tree: 1) After calibrating your 45 degree technique on a height that you can measure, go outside and spot a tall tree that you could possibly walk up to. 2) Spot the top of the tree by bending over and looking through your legs so that you can just barely see the tip top. Adjust your positioning relative to the tree as needed. 3) Mark your spot and either measure out using a metre stick, or just pace it out to the base of the tree. Whatever distance you measure to the tree is the height of the tree, so long as you got your 45 degree angle correct.
***It sometimes helps to have a friend spot you from a perpendicular angle of your observation to make sure that you are about 45 degrees to the top of the tree.