SOLUTION: I have been out of high school and college for over 4 years now...so I used to know the answer, but we are far from it now! I am looking for the "rules" or "formula" or "whatever"

Question 147089: I have been out of high school and college for over 4 years now...so I used to know the answer, but we are far from it now! I am looking for the "rules" or "formula" or "whatever" that makes this a correct statement. You have a triangle with a right angle. Side A =3ft Side B=4ft (side A and B are connected by the right angle). We know that side C (the hypotonus) =5ft. I want this equation in a larger term (ie Side A=10ft Side B=20ft what is side C) Thanks so much for your help! I actually miss doing this on a regular basis! I loved math in high school, and now it just helping my dad build a cabin. Thanks again. Michelle Wagner
Found 2 solutions by jim_thompson5910, solver91311:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
We basically have this triangle set up:

Since we can see that the triangle has legs of 10 and 20 with a hypotenuse of x, we can use Pythagoreans theorem to find the unknown side.

Pythagoreans theorem:

where a and b are the legs of the triangle and c is the hypotenuse

Plug in a=10, b=20, and c=x. Now lets solve for x

Square each individual term

Combine like terms

Take the square root of both sides

Which approximates to...

So our answer is

which means that

It might make more sense to round to the nearest hundredth to get

Now take the decimal portion 0.36 and multiply it by 12 to get 0.36*12=4.32

So the length of C is about 22 feet 4.32 inches
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
Use the Pythagorean Theorem. For a right triangle where the legs are and , and the hypotenuse is , , so .

For your example:
and , roughly 22.36 feet or about 22 feet, 4 and 3/8 inches. That ought to be close enough for log cabin building.

To do the decimal to feet/inches conversion, take the decimal part of the measurement and multiply times 12. .36 X 12 = 4.328 roughly. Now compare the decimal part of that result to the following table:

1/8 = .125
1/4 = .250
3/8 = .375
1/2 = .500
5/8 = .625
3/4 = .750
7/8 = .875

Pick the decimal value closest to the decimal part of your calculation and use the corresponding fractional value. That gets you within 1/8 inch which should be close enough. .328 corresponds most closely with .375, so 3/8 inch. Putting it all back together: 22 feet, 4 and 3/8 inches.

Hope that helps
RELATED QUESTIONS
-2x-18=4x It's been a while since high school, I used to know how to do this simple... (answered by stanbon)
I am not sure if this the right subject to put this under but... I am helping a friend... (answered by solver91311)
I just statred college after I was off for 10 years. In high school I loved it and did... (answered by bucky)
multiply both side of the equation by a common denominator to eliminate the fractions. (answered by mananth)
I'm three times as old as you were when I was as old as you are now. When you will be my... (answered by ikleyn)
when I get the fraction 12/11...I understood all that pretty easily..but it's been a... (answered by ankor@dixie-net.com)
ok so im studying and i haven't been in school for about three months and there are a lot (answered by stanbon)
Multiply both side of the equation by a common denominator to eliminate the fractions. (answered by Earlsdon)
Hi, I am having problems with a chi-square related question. Here is the question: (answered by stanbon)