## anonymous one year ago triangle help plz

1. nerdyotter

2. anonymous

|dw:1439402369884:dw| Given that:AB-8 BC=3 DE=13 BD=x What is the value of xx?

3. anonymous

@ganeshie8 @Hero @pooja195

4. nerdyotter

I'd say just set up a ratio between the corresponding sides of the triangle and use substitution to find the value of x, then multiply x by itself.

5. anonymous

ok imma be real with u but i only got x part and multiply it now slow down and explain

6. anonymous

@heretohelpalways

7. nerdyotter

If you'll notice, since triangle ABC and triangle ADE both share point A, they are similar triangles. This means that we can set up a proportion between sides AB and AD, and sides BC and DE.

8. nerdyotter

It would look like this, $\frac{ AB }{ AD } = \frac{ BC }{ DE }$ This is a proportion between the side lengths of the smaller and larger triangles. Now all you have to do is substitute to find the value of x. I'll explain further.

9. nerdyotter

Since AB is 8, we would substitute that value in for the proportion. This continues with the other values until we arrive at... $\frac{ 8 }{ 8 + x } = \frac{ 3 }{ 13 }$ All you have to do now is cross multiply and you'll be able to find the value of x.

10. anonymous

wht pellet im fried im lost again ahhhhhhhh my brain

11. nerdyotter

@jamesr Where have you been able to follow up to?

12. anonymous

the part where it would look like ...

13. nerdyotter

Are you talking about the proportion I set up? The second proportion I set up is the same as the first one. All I did was substitute in values. In simpler terms, if we're trying to find... $\frac{ AB }{ AE } = \frac{ BC }{ DE }$ This proportion is the exact same as... $\frac{ 8 }{ 8 + x } = \frac{ 3 }{ 13 }$ The only thing the second proportion is doing is substituting in the values of AB, AE, BC, and DE.