For my first mathematical post, I'm going to explain the Pythagorean Theorm. The name makes it sound scary but I guarentee you it is very simple once you understand it.
Now, rule number one- this theorm only works with RIGHT TRIANGLES
Rule number two- you can use it to find the length of ANY side of a right triangle so long as you have the lenght of two other sides.
And now for the Theorm itself:
a^2+b^2=c^2 Yep, that's it. It would look nicer if this thing was more exponent friendly but still.
Now, for the explanation:
First, since I can't get a picture on here, draw a right triangle. Then you're going to label the legs (the straight sides) a and b, it doesn't matter which one you label which way. Now label the other side, the slanted one (technically it's called the hypotenuse, but 'slanted side' is easier to say), c. Now write in measures for sides a and b; use the measures 3 and 4 if this is your first time because you'll get some nicer numbers.
Now, plug the numbers you have for sides a and b into your formula (assuming you used 3 for side a and 4 for side b), and you should have something that looks like this:
3^2+4^2=c^2 (the symbol that looks like a roof-top, ^, like that, is another way of writing a number raised to a certain power, so in the formula you ought to have right now, it will read 3 to the second power plus 4 to the second power equals c to the second power)
Now, simplify what you've got: (when you raise something to a power, you multiply it by itself however many times the exponent (the tiny number at the top right or the number right after the roof-top sign) tells you. So if you had 6^2 it would be 6 times itself twice; like this: 6x6 and that would give you 36 :) )
9+16=c^2
Now, to solve for the variable you don't know (or the side you don't know - which, in this case, is shown as c ), simplify the '9+16' bit ( it equals 25). Now you still have the c to the second power to get rid of; to do that, you have to take the square root of both sides (what you do on one side of the equal sign, you have to do to the other, and if you don't know what the square root symbol looks like, just imagine a long division bar that has a check-mark-like thing on the shorter end). Since taking the square root of something is the opposite of raising it to a power, the c squared under the square root bar (more specifically called the radical bar, that's what I'm gonna call it from now on) cancel out, you should just have c on one side of the equal sign. Since you have to do the same thing to both sides of the equation, you also have to take the square root of 25. Now, to take the square root of something, you have to find a number that, when multiplied by itself, equals the number you're taking the square root of; in this case, when you take the square root of 25, you get 5 (since 5x5=25, 5 times itself equals 25; that also makes 25 a 'perfect square" just FYI)
After all that you should have:
5=c which gives you the measure of the missing side of the triangle I had you draw earlier... you can do this with any right triangle that has two side measures given- and they don't always have to be the two legs of the triangle that are given to you, it could be the hypotenuse (the slanted side) and a leg- just remember to plug in your measures given into the equation.
If you have any questions, leave a comment, and I'll get back to you as soon as I can! Happy mathing!
Remember- if you need extra help on this go to www.khanacademy.org
and type in Pythagorean Theorem and a bunch of videos will pop up.
-Bye :)
No comments:
Post a Comment