Use the triangle at the right. Find the length of the missing side.
1. a = 16, b = 63 2. b = 2.1, c = 2.9
i need help

Question

Use the triangle at the right. Find the length of the missing side.
		1.   a = 16, b = 63		2.  b = 2.1, c = 2.9	
 i need help

e.mccormick · Answer

OK.  So what triangle?

e.mccormick · Answer

If it is a right triangle, you can use the Pythagorean Theorem.  But for other things, you may need trig.

anonymous · Answer

i need help with all of this i dont understand any of it

e.mccormick · Answer

Ah, right triangles!  Pythagorean Theorem it is! 

|dw:1366728193777:dw|
If this is basically any right triangle, then $x^2+y^2=h^2$  h would be the hypotenuse.

Familliar with that one?

anonymous · Answer

yes

e.mccormick · Answer

Great!  Well, in your problem, they are using a, b, and c.  Which one is the hypotenuse?  Once you know that, it is just a matter of writing it properly and solving for the unknown.

anonymous · Answer

the hypotenuse is c

e.mccormick · Answer

OK.  So the formula becomes: $a^2+b^2=c^2$  So, replace a, b, and c with what you know.  

In #1 it is a = 16, b = 63, and solve for c.  

In #2 it is b = 2.1, c = 2.9, solve fora.

anonymous · Answer

so ifon number 1 a=16 and b+63 then c the hypotenuse =79

anonymous · Answer

and if b= 2.1 and c= 2.9 then a=.8

e.mccormick · Answer

You need to use the squares.  Let me show you the first one.
$a^2+b^2=c^2 \implies (16)^2+(63)^2=c^2  \implies 256+ 3969 = c^2$
See where that is going?

e.mccormick · Answer

So I have $4225=c^2$ but what I need is c.  So then I take the root. $\sqrt{4225}=c$ If I find the root, I am done.

e.mccormick · Answer

So $c=65$.  Do you see why the squares make such a huge difference in the answer?

anonymous · Answer

yea

e.mccormick · Answer

OK.  So do the second one again, but remember to square, do the addition or subtraction in that case, then find the root.

e.mccormick · Answer

Ooh.  Nice number to get a root of in that one.  Should be an easy answer once you do the squares properly.

anonymous · Answer

ok im lost im problem 2 ivde tried and messed up

e.mccormick · Answer

What did you try?

e.mccormick · Answer

Had some connection problems...  Look at this:
$a^2+(2.1)^2=(2.9)^2$  You need to square the numbers.  Then, whatever you get for the replaced b needs to be moved over to the other side, which means subtracting it.  Finally, you will do the root of both sides to turn $b^2$ into b and whatever number is on the right into the answer.

I have to go now, but I hope that is enough to get you through.

The next question, with the ladder, it the same basic thing.  Just need to pick out what to put into the formula.