Posted by Anonymous on .
How do I find a missing length to a triangle? The lenths I have are 18 for one side 27 for the other and (x) for the bottom length. Then for the other triangle given the lengths are 14 for one length, 21 for the other length and 28 for the bottome length. I am trying to solve for x?

MathTriangles 
Sara,
Use the pythagorean formula(a²=b²+c²)
a= hypotonuse
b= side
c= side 
MathTriangles 
Anonymous,
I don't understand. There are two triangles, they are called similar triangles.
The first triangle has
Side A is 18
Side B is 27
Side C or hypotonuse is x
Second Triangle
Side A is 14
Side B is 21
Side C or hypotonuse is 28 
MathTriangles 
Sara,
for the first one:
The first triangle has
Side A is 18
Side B is 27
Side C or hypotonuse is x
you are trying to find the hypotenuse right? The hypotenuse of a right triangle is the longest side. The square of the hypotenuse is equal to the sum of the squares of the other two sides. You have the length of the other two sides which are 18 for side A and 27 for side B. Now you just have to square them, add them together and take the square root. 
MathTriangles 
Sara,
I don't understand what you're solving for the Second triangle. You have both the side lengths and the hypotenuse. Are you trying to find the area of this problem?

MathTriangles 
Saracan you help me with this problem,
I am not getting the correct answer. And what is the significance of the second triangle?

MathTriangles 
Anonymous,
That was my question as well. I believe this is solving for similar triangles...or why else would the second triangle be part of the problem? What is the significance of the second triangle? And I am not getting a legitimate answer solving for x.

MathTriangles 
Anonymous,
I think it is 36. The difference between side A is 4 and the differences between side B is 6, so the difference between side c would be 8, I just don't know how to show the calculations.

MathTriangles 
jim,
I answered this below, but you didn't specify that the triangles are similar in the original question.
That means that the clue is in my original answer. 
MathTriangles 
Anonymous,
Ah! okay! I will go check it out!

MathTriangles 
Sara,
sorry, I explain it more clearly to you.
for the first one:
The first triangle has
Side A is 18
Side B is 27
Side C or hypotonuse is x
The sum of the areas of the squares attached to the hypotenuse equals the area of it. Ex. The hypotenuse is A©÷ and the other 2 are B©÷ and C©÷. A©÷+B©÷=C©÷
Example find the area of square attached to hypotenuse:
C©÷ =A©÷+B©÷
=2©÷+4©÷ (2*2) +(4*4)
=4+16
=20cm sqared.
other examples: A©÷+B©÷=C©÷ = C©÷=A©÷+B©÷
C=hypotenuse A/B= 2 legs/sides
this is applied only to right traingles.
finding length of hypotenuse when lengths of 2 legs are known
C©÷=a+b
C=(3)+(4)
C=9+16
¡îC =¡î25
C=5
sorry i don't know how to put the square sign. Hopefully my examples will help. I don't have math this semester, that's why it's kin of hard for me to help you. 
MathTriangles 
Sara,
OMG that is really wierd I don't know where the © came from. This is seriously not what i wrote.

MathTriangles 
Sara,
Never mind, I think Jim has helped you:) All the Best.

MathTriangles 
jim,
Sara, I understand what you're doing, but I think the question wasn't put clearly.
Neither of the triangles here is rightangled.
The two triangles are similar: their sides have the same ratio.
We know one is 2*7:3*7:4*7 and the other is 2*9:3*9:x and we need to find x. 
MathTriangles 
Sara,
Oh, no wonder, Now I understand, thanks.

MathTriangles 
Anonymous,
Thank you both of you. Sorry to confuse you guys. Yes, the triangles are similar. I think I solved it, is x 36?