Now, if you want to know a numerical value for , you have to know numerical values for and . Let's suppose that and . Just plug those numbers into a scientific calculator, and you get . Subtract 2 from both sides, so Take the square root of both sides, so . If you want a numerical value for , you need to know .
Scientific notation takes the form , and the rule is quite simple.
If is positive, move the decimal point places to the right. If is negative, move the decimal point places to the left. The main fact that we will use in geometry is the Pythagorean Theorem. The Pythagorean Theorem is quite simple. Suppose you have a triangle like the one at the left.