If you need to measure the distance to a moving object, then use the tactic of closing the eyes. Take, for example, a person who is on the opposite Bank of the river.
To find the distance to a moving pedestrian, extend your arm in the direction of movement of the traveler and focus your eyes the right eye at the end of the index finger until the person closes to them.
At this point, close the right eye and open left. The traveler while supposedly will bounce back.
Now count how many steps will make the pedestrian before you reach your finger.
The distance to the traveler, which is on the opposite Bank, calculate from proprcia: D / P = L / G where D is the desired that you want to calculate in steps P – distance, which has passed the pedestrian (even if it is for example equal to 18 steps), L – the distance from the end of the arm to the eyes, it is on average equal to 60 cm, G – the distance between the pupils, it is on average equal to 6 cm. From the formula it follows that D = N x L / G. the result is: D = 18 x 60 / 6 = 180.
Knowing that one step is equal to about 0.75 m, calculate the distance in meters: 180 x 0.75 = 135 m. This distance is passed the traveller on the opposite Bank of the river.
If you need to determine the distance nedvizhemost objects, then apply the tactics of grass. Take, for example, the river width where you need to determine.
To start, click on the opposite Bank of the river two visible object located as close as possible to the water.
Stand on the very edge of the shore, take in both hands the blade of grass and stretch your arms in front of him, one eyes close.
Fold the blade in half and start to move away from the coast up to that time, while the distance between the two wybranymi objects are not closed by the blade of grass.
Now measure the distance at which you had to move from the beginning shore, and you will get the width of the river.