From the foot of the object you are to measure pace eleven (11) units, we label it distance AB. A unit can be any number of paces, so if we say our unit is five paces then 11 units is equivalent to 55 paces. Place something to mark the point B. From B take one more unit forward, this is distance BC. From location C lie down on the ground such that your eyes are close to the ground as possible. Sight the tree with the marker on B in your line of sight. Note where your line of sight cuts the marker to the tip of the tree. That spot is labelled as D. The distance of BD in inches is the estimated height of tree in feet.