Wednesday, November 18, 2009

Review of 3.1, 3.2 and 3.3

If A=15 cm2, B=5 cm2, then C would have to be 20 cm2. You see, in order for the triangle to be a right triangle the legs (two sides which are not the hypotenuse... the hypotenuse is the side opposite the right angle) area in A and B must equal the area of C. The Pythagorean Relationship states that A2 + B2 = C2.


The Pythagorean Relationship can also be used in real life, it has to be used for the highways and on buildings.
"The construction workers wouldn't go out to the highway with a little protractor to measure a ninety degree angle." Those words were straight from the lips of Mr. Oldcorn.


Many people got 13.C) wrong on the page we were correcting, it was...
'If B is 25 cm2 and C is 90 cm2, What is A?' The thing people did wrong was that they added 25 and 90, HOWEVER, it said what is A! A isn't the hypotenuse therefore, you don't add you, subtract so... C-B=A = 90-25=65 cm2 So A was 65 cm2!


Another thing we went over is square root, for example, you know the square root of 36 is 6. But how do you figure it out? Well, there is three ways to do so 1. Prime Factorization 2. Guess and Check 3. Calculator But what if you had a number that doesn't have a whole number for the square root. Like 51. Question, How would you find the square root of 51 without a calculator. Well you couldn't easily do it with prime factorization. So you can guess and
check. But to do so first you have to find the closest two numbers. 51 would be 7x7=49 and 8x8=64. Once you know that you need to figure out whats halfway between. Half between 49 and 64 is 56.5 and 51 is closer to 49 than 64 so it's closer to 7 too. Which would mean it'd be around 7.2 .


After that we had a class vote, we could either have a quiz on 3.1, 3.2 and 3.3 or wait until the end of the unit and have a big test. It turned out more people would rather have a halfway test then a bi
g test. We assigned the quiz for Monday, however, the date might change. You should probably start hitting the books for Monday!

This is a diagram of a right triangle to show you which are the legs and the hypotenuse.

2 comments:

  1. Excellent post Gilles!!!

    When you put your mind to it, you can really do great things.

    (Might want to increase the size of the font. Don't worry about how much room it takes up.)

    ReplyDelete

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