I measured the height of the 183CM when barefoot in the school, but I always thought that I 183CM, yesterday to a friend's house to play, see a steel tape, is very curious and take it out. The amount of height, my 181CM, what this situation? Did I shrink when I was 15? How do you get that broken steel tape measuring 181CM? Still not allowed? Is that my school or this?.
I don't know. Anyway, I used to measure height, wear shoes is 167, and later grew three centimeters, that day with a rigid tape measure is actually 165, I grass.
General rule of small expansion coefficient, measured relative accuracy, measured winter than summer high, it is not a ruler of expansion and contraction.
Steel tape, thermal expansion and contraction is insignificant, and now is the winter, only because of the amount of contraction, the result of higher.It is because of the amount of error when you, now and in the school when the amount was not the same way, or inaccurate, or parallax error, 2CM is possible, sometimes bow rise, error occurs. You can lean against the wall, head forward, let others help you, put a board over your head, mark the wall, and mark the distance to the ground. This is closer to reality.
