The premiters of two equilateral triangles are in the ratio 2:3. If the perimeter of the smaller triangle is 16 cm what is the measure of a side of the larger triangle?

Permimeter is a linear ratio (3:2), and ratio of sides is also a linear ratio (3:2). SO if the shorter is 16, the longer one is 16*3/2=?

could I do it in a proportion?

Yes, you could do it in proportion as long as both measurements are linear, e.g. perimeter and side.

how?

...SO if the shorter is 16, the longer one is 16*3/2=?

I got 10 something but it's not one of the answers

16*3/2 has to be greater than 16, how did you get 10?

3/2 = .6 repaeating x 16 = 10.6 repeating

and 16/1 x 2/3 = 10.6 reapeating

3/2 = 3 divided by 2 = 1.5

Think of
(16*3)/2 = ?
That should make it easier!

But that equals 24 and that not a answer on the thing

Sorry, I misread the question (too fast).

The perimeter of the smaller triangle is 16 cm, so the perimeter of the larger triangle should be 24 as you calculated. However, since 24 is the perimeter of three equal sides, each side should measure 24/3=8 cm.
Make sure you understand how it is to be done, or else you will get stuck on the next problem.

Ok I get it. Thank you!!!

Also, it would help if you could give your first name or a pen-name of your choice so next time I would know we worked together before.