Question

help please.
fan and medal.
The triangles are similar by the AA Similarity Postulate.
Find the value of x.

Answer 1

i hate triangles now...more than ever!

Answer 2

Triangles are beautiful. Look at them. Admire these triangles. Math built these.

Answer 3

Anyhow, what you're going to want to do is set up a proportion.



this should give you a little jumpstart\[\huge \frac{4}{5}=\frac{?}{?}\]

Answer 4

\[\frac{ 8 }{ x }\] would be for the second fraction

Answer 5

that's going to be one of the common mistakes students are going to make.

The comparison is The side of the little triangle to the bottom of the little triangle.

The side of the big triangle to the bottom of the big triangle.

Do you see how the black lines I drew extend the whole length?

Answer 6

yeah i see them

Answer 7

So the second fraction isn't going to be 8/x

it's 8+4/x because we're taking the WHOLE triangle

Answer 8

oh ok

Answer 9

so...?
\[\huge \frac{4}{5}=\frac{8+4}{x}\]\[\huge \frac{4}{5}=\frac{12}{x}\]

Answer 10

then you'd do like cross multiplication to get 4x=60 then divide by 4 and get 15 right?

Answer 11

yup yup yup yup

Answer 12

whooo! see the problem for me there was trying to figure how to get the fraction for it right cause i'd always put the numbers in the wrong place

Answer 13

Eventually when you take chemistry, you'll use an idea similar to this. Basically, you make sure the units are always the same so that you're always comparing the same units.

\[\huge \frac{smallside}{smallbottom}=\frac{largeside}{largebottom}\]

so you have to think about what the large triangle's side is. In this case it's 8+4 because you're comparing the whole triangle

Answer 14

oh alright cool i get it now :>

Answer 15

like that. glad to hear