# Thread: Simple geometry

1. ## Simple geometry

Given that triangle A has its legs with lengths 4 and 7, you want to create another triangle B that's similar where the smaller leg has a length of 5. Determine the length of the other leg. Then determine its hypotenuse.

My solution:

4/7 = 5/x means that x = 35/4 so that's the length of the 2nd leg

Then, I am assuming the hypotenuse will be proportional if the sides are (by default), so it is then:

(35/4)^2 + 5^2 = x^2 means that x = 5*sqrt(65)/4

Is this right?

2. $

x= \sqrt{(\frac{35}{4})^2 + 5^2}

$

I don't know what you did there but if you calculate your x you get twice as much than it really is.

3. Originally Posted by metlx
$

x= \sqrt{(\frac{35}{4})^2 + 5^2}

$

I don't know what you did there but if you calculate your x you get twice as much than it really is.
Um, that equals 5*sqrt(65)/4 so I guess I was right.

4. ah yea. sorry about that.
i thought it was the square root of (65/4). not square root of 65 which is then divided by 4. hence why I got twice as much using your method.