The thumb distance measurement method is measured according to the right triangle function.

Suppose there is a target n meters away from us, and measure the distance from us to the target:

1. Raise our right arm horizontally, make a fist with our right hand and stand with our thumbs.

2. Overlap the left side of the thumb with the target object and form a straight line with the right eye (the left eye is closed);

3. Keep your right arm and thumb still, close your right eye, and then observe the left side of your thumb with your left eye. You will find that this sideline is a distance from the right side of the target;

4. Estimate the distance (this can also be measured), the distance × 10, and the number is the approximate distance from our target.

Attached is the naked eye ranging method commonly used in China and the United States:

Snipers in China's army and police generally use the eye-jumping method: clench the right fist with the thumb up, extend the right arm horizontally, close the left eye, and observe the target with the right eye just on the side of the thumb. At this time, keep your posture, close your right eye, and observe another reference object with your left eye on the same side of your thumb-the distance between the reference object and the target multiplied by 10, which is the actual distance between you and the target.

The US military is somewhat similar: clench the right fist, put the thumb flat, extend the right arm horizontally, close the left eye, and observe the target with the right eye just above the thumb. If the target just crosses in one step, you are 65,438+000 yards away from the target; if the target just crosses in two steps, you are 200 yards away from the target. .............................................................