# Thread: I need to find the values of x and y.

1. ## I need to find the values of x and y.

There are 2 similar triangles.

one small triangle and a larger one.
The small one has sides that are 15, 20, and 25.
on the big one in the same order, 24, y, and x.

How do I find x and y?

2. Originally Posted by robin1
There are 2 similar triangles.

one small triangle and a larger one.
The small one has sides that are 15, 20, and 25.
on the big one in the same order, 24, y, and x.

How do I find x and y?
do you have diagrams? for the triangle with sides 24,x and y, which is the smallest, middle and largest side? are we to assume 24 < y < x ?

3. ## value of x and y

I do have diagrams.

The small triangle, 15 is the shortest 20 is middle and 25 is longest.
The big triangle, 24 is the shortest, y is middle and x is longest.

4. Originally Posted by robin1
I do have diagrams.

The small triangle, 15 is the shortest 20 is middle and 25 is longest.
The big triangle, 24 is the shortest, y is middle and x is longest.
the triangles are similar, thus their side lengths are proportional. that is, for instance:

$\frac {\mbox{The longest side of the small triangle}}{\mbox{The shortest side of the small triangle}} = \frac {\mbox{The longest side of the large triangle}}{\mbox{The shortest side of the large triangle}}$

and

$\frac {\mbox{The middle side of the small triangle}}{\mbox{The shortest side of the small triangle}} = \frac {\mbox{The middle side of the large triangle}}{\mbox{The shortest side of the large triangle}}$

5. ## value of x and y

then I come up with:
25 = x
12 24

and
20 = y
15 24

How do I now solve this?

6. Originally Posted by robin1
then I come up with:
25 = x
12 24

and
20 = y
15 24

How do I now solve this?
you tell me

let's start with $\frac {25}{15} = \frac x{24}$

how would we isolate x? that is, get x on one side of the equation by itself. that is, get rid of the 24 that is dividing it?

7. ## value of x and y

it is actually:

25 = x
15 24

then
20 = y
15 24

I think that I need to cross multiply
25*24
15x
15x=600
x=40

20*24
15y
15y=480
y=32

8. Originally Posted by robin1
it is actually:

25 = x
15 24

then
20 = y
15 24

I think that I need to cross multiply
25*24
15x
15x=600
x=40

20*24
15y
15y=480
y=32
correct

9. ## value of x and y

Thank You so much!!!!