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3-4-5 Rule

Vaughn McMillan said:
I consider myself almost mathematically illiterate. Factor an algebraic equation? I have no idea. I can't tell a cosine from a street sign. But give me a practical application for that math and show me how to do the calcs, and I'm all over it. I've had a number of jobs that used a lot of math and had no problem with it as long as it was real-world stuff and not theories.
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We would educate our youth better in my estimation if we did more of this in the classroom. I got more out of my shop math class, than I ever did in any "real" math classroom.
 
Jonathan Shively said:
We would educate our youth better in my estimation if we did more of this in the classroom. I got more out of my shop math class, than I ever did in any "real" math classroom.
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My dad only went through the 8th grade in school, but was a pretty accomplished carpenter. When I went into high school algebra and got stuck on a problem, I could read the problem to him and he could give me the answer... but never could tell me how he arrived there...
 
Jonathan,

There are three sides to a right triangle. The opposite and adjacent are the short sides and they hypotenuse is the longest side. If one angle is 90 degrees then the Pythagorean theorem applies.

The square of the hypotenuse is = to the sum of the squares of the other two sides.

In the case of the 30-60-90 triangle this works like this.

3x3 = 9
4x4 = 16
5x5 = 25

It just so happens that 9+16 (sum of the squares) is equal to 25. 3,4,5.
 
Actually Roger the 3/4/5 right triangle is not a 30°-60°-90° triangle, it's a 36.8699°-53.1301°-90° triangle.

Proof:
Sin 30°=0.50000, Sin 60° =0.86603
Cos 30°=0.86603, Cos 60°=0.50000

Sin 36.8699°=0.60000=3/5
Cos 36.8699°=0.80000=4/5
 
Maybe we need to hand these out...

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:D

Just kidding. ;)
 
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