A group of managers is trying to calculate the height of a flag pole. They try to measure its height by lining up their thumbs and then turning the thumb 90 degrees and marking a spot on the ground. Then they try to use its shadow and trig functions, but no luck.
A engineer comes by and watches for a few minutes. He asks one of the managers what they're doing.
"We're trying to calculate the height of this flag pole."
The engineer watches a few minutes more and then, without saying a word, he walks over, pulls the pole out of the ground, lays it down, measures it, writes the measurement on a piece of paper, gives it to one of the managers and walks away.
The manager looks at the paper, snickers and says to the other managers: "Isn't that just like an engineer?! We're trying to calculate the height and he gives us the length."